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Today in New York Weather History: September 26

 

1940

Clear skies and very chilly, with a high/low of 60°/42°, which made it feel more like early November.  The morning low, 15 degrees below average, was a record for the date (which still stands).  This chilly air followed a rainstorm that swept through yesterday morning, dumping 2.36" of rain (a record for the date that also still stands).  This accounted for almost all of September's 2.82" of rainfall. 

1970

Between Sept. 22 and today, four of the days had afternoon highs in the 90s: 94°-93°-87°-90°-91° (today).  Furthermore, all five days had mean temperatures that were fifteen degrees or more warmer than average.  Yesterday and today's highs were records for the dates; today's was the latest 90-degree reading since 1941.  

1975

For the fourth day in a row, more than an inch of rain fell.  At the onset of this deluge rain fell for 47 consecutive hours.  Total rain during these four days amounted to 7.43", as 1.82" fell today; 1.05" yesterday; 2.26" on 9/24 and 2.30" on 9/23. 

 

Weather.downpour on umbrella 

1993

Beginning at 11 PM last nigh,t and continuing through 10:00 this morning 1.66" of rain fell.  It came down heaviest this morning when an inch fell between 6:45-8:45 AM.

1995

This was the seventh year in a row that rain fell on this date.  The 0.42" that fell today occurred throughout the day.

2005

Evening showers amounted to 0.17", the "rainiest" day of what turned out to be the driest September since 1884.  By contrast, September 2004 had 11.51" of rain, the wettest since 1934.

2007

Today's high was a sultry 87°, fourteen degrees warmer than average.

2008

The morning was very soggy as heavy rain amounted to 2.34", most of which fell between 3-10 AM.  This was a record rainfall for the date.

 

Morning_rainstorm

 

2018

A new September record was set as the day's low of 69° was the seventeenth this month that was 67° or warmer, breaking a tie with 1971.  (A typical September has six days with lows this mild.)

2020

This was the sixteenth day in a row with no measurable rain, one day more than June's dry streak, which had been the longest this year.  The last time there was a lengthier streak was during the fall of 2017 when there was one of eighteen days (Sept. 20-Oct. 7). 

16 days

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August 2021 Weather Recap: Henri Rescues August From "Dullsville"

 

 Hurricane henri aug 2021

 

August was the fourth wettest August on record, but until 8/21 the month had been a dry one, with rainfall 50% below average.  Then, Hurricane Henri produced 8.19" of rain over three days (Aug. 21-23), accounting for nearly 80% of August's 10.32" of rain.  (The other 28 days of the month had just 2.13".)  This was the second month in a row with more than ten inches of rain (July had 11.09", making it the third wettest July),  just the second time this has happened (however, the first time, in March and April 1983, is disputed since the rain gauge in Central Park wasn't functioning properly for much of the year).  Although August's rainfall was less than an inch below that of July, its number of days of measurable precipitation was half as many (nine vs. eighteen).

 

Chart - rainiest back to back months
 

One out of four Augusts have been warmer than July, and August 2021 was one of them (77.5° vs. 76.0°).  The month was 1.4 degrees above average, making it the City's 17th hottest August (out of 153).  However, there was a disparity in rankings of the average high and low, as only five other Augusts have had a warmer average low than this August (2.2 degrees warmer than average), but the average high (just 0.6 above average) was ranked much lower, at #39.  This difference in rankings wasn't unique to this August, as the trend during the 2000s has been for overnight temperatures to be more above average than daytime readings (one of the effects of global warming).

 

After the first five days of the month were five degrees below average, the rest of the month was three above average (with only five of the 26 days having cooler than average mean temperatures).  August had five readings in the 90s, one more than July, and it had five more days than July with lows of 75° or warmer.  August's days in the 90s were comprised of back-to-back days on Aug. 12-13, and a three-day heat wave two days after Henri's departure (Aug. 25-27).  The month's hottest reading was 94° on 8/13.

 

Finally, this was the eighth year in a row in which August had no readings in the 50s.  The coolest temperature was 63° on 8/2.  (Meanwhile, July's streak of 12 years with no lows cooler than 60° was broken this year). 

Henri

Here are monthly recaps for past Augusts:

2020

2019

2018

2017

2016

2015

 

 

 

 

 

 

   


July 2021 - Third Rainiest July Keeps Mid-Summer Heat in Check

 Noahs ark in water

With 11.09" of rain measured in Central Park, July 2021 became the third rainiest July on record (behind 1889 and 1975), and 15th wettest month overall.  This was New York's first month with ten inches or more of precipitation since June 2013 (10.10"), and the most to fall in any month since August 2011, when 18.95" flooded the City (the greatest monthly amount on record). 

 

A little more than half of July's rain fell on three days between July 8-12: 2.27" on 7/8; 2.06" on 7/9, and 1.42" on 7/12.  The amounts of 7/8 and 7/9 set records for the dates.  8.49" of rain fell in the first 12 days of the month (and 9.14" if 6/30 is included), then 2.60" fell thereafter (which was slightly below average for that period). 

 

There were 18 days of measurable rain, which was the second greatest number of days with rain in July.  July 1871 had twenty days, but just half the amount of rain as July 2021.   (Of the 27 months with ten inches or more or precipitation, the average number of days of measurable precipitation is 13.) 

 

Besides being rainy, this was the coolest July since 2009 (and 0.1 degree cooler than July 2014).  When all Julys are considered, July 2021 is in the middle of the pack, temperature-wise, with 54% being warmer.  The combination of a warmer than average June (+2.3 degrees), and July being 1.5 degrees cooler than average, placed these two months closer together (1.7 degrees) than any June/July combo since the summer of 2001 (when July was just 0.3 degree warmer).  Looking at average high and low, July's average high of 83.0 was just 0.5 degree warmer than June's, while the low of 69.0 was 3.0 degrees milder.  Because many days had dew points in the 68°-73° range, the air often felt oppressive rather than cool.

 

So close_colbert
 Chart - july close to june

For the first time since 2009, a reading in the 50s occurred in July - 59° on 7/3.  And on 7/3, the high was only 66°, which was the first high cooler than 70°in July since 2013, and the coolest reading in July since 2005 . The month's coolest and hottest readings were three days apart as a high of 92° occurred on 7/6 (and the 59° reading came three days after June's hottest temperature, 98°, on 6/30).

 

July had four days in the 90s, half as many as June, and the fewest such days in July since 2014, which had three.  (Seven of the Julys between 2000-2009 also had four or fewer days in the 90s.)  Although the number of days of 90+ was half the average for July, the number of lows in the 70s, 16, was an average am0unt (but ten fewer than last year's record amount).

 

July had 8.47" more rain than June's 2.62", but there have been ten other instances where the disparity between two months was even greater (looking only at wet months preceded by dry ones).  The greatest difference occurred in  Sept-Oct 2005, when October had 16.73", which was 16.25" more than September's bone-dry 0.48".

 

Chart - greatest dif in precip btwn 2 mos

Finally, after suffering through sweltering heat, and a nighttime thunderstorm on the last day of June, the last day of July couldn't have been more different, as skies were clear and temperatures on the cool side (high/low of 77°/60°).  While 6/30's high of 98° (14 degrees above average) was the hottest reading on that date since 1964, 7/31's low of 60° (ten degrees below average) was the chilliest since 1956.

 

July 2021
 

Here are other July recaps:

July 2020

July 2019

July 2018

July 2017

July 2016

July 2015

July 2014

 

 

 

 

 


June Weather Recap: Two 4-Day Heat Waves Make June 2021 One of NYC's 10 Hottest

 City sunflower 2021

With a scorching high of 98° on the last day of the month (along with a heat index of 106°), June 2021 became New York's ninth hottest June.  This was Central Park's hottest temperature since 2013, and the hottest reading in June since another 98° high in June 1994.  6/30 was also the last day of the month's second four-day heat wave, which was just the second time there were two heat waves of this length (or longer) in June (the other was in June 1943, the hottest June on record). 

 

The month's eight days with 90+ highs were the most in June since June 1991 (which had nine).  Only four Junes have had more hot days: 1943 (11), 1966 (10), 1925 (9) and 1991 (which was slightly cooler than June 2021, ranking as 14th warmest).

 

The month had nine days with lows in the 70s, tying it for ninth most in June.  The month's five days with lows of 75° or warmer was the most since there were six in June 1943.  (June 1909 had the same number as this June.)  Finally, in the years since 1940, the low of 76° on 6/6 was the fifth earliest date for a low this warm.

 

Ironically, despite the month's warmth, this June had the latest occurrence of a reading in the mid-50s since 1995, occurring on 6/23 (54°).  This was the coolest reading of the month (twelve degrees below average).

 

The month's two four-day heat waves were three weeks apart - June 6-9, and June 27-30.  The first heat wave averaged a high/low of 91°/74° (13 degrees above average), the second was 94°/75° (nine above average).  Both heat waves had a day with significant rainfall at night, 0.47" on 6/8, and 0.65" on 6/30.  Without these heat waves, the other days of the month were one degree cooler than average.

 

Besides the high of 98°, the last day of June was also the rainiest day of the month (0.65").  If it hadn't been for this rainfall, this would have been the second June in a row with less than two inches of rain, something that hadn't happened since 1978 and 1979.  These nighttime thundershowers cooled the temperature to 73°, erasing the day's morning low of 80°.  (If that sultry low had remained the day's low, this would have been the seventh, rather than ninth, hottest June.) 

 

With eight days of 90+ readings by 6/30, 2021 joined 20 other years (since 1869) to have this many by that date (1991 had the most - 15).  The last time there was this many by this date was in 1994.  Prior to that, between 1923-1994, this many days in the 90s by the end of June occurred much more regularly, once every four years.

 

Finally, in an interesting contrast, while the last four days of June had highs in the 90s (eleven degrees above average), the last four days of May all had lows in the 40s (ten degrees below average).

 

Girl_cooling_off_in_fountain_ethiogrio

Here are previous June recaps:

2020

2019

2018

2017

2016


May 2021 Weather Recap: Close to Average Temperature & Rainfall Despite Very Chilly & Wet End

 Wet and chilly memorial day weekend

Last May, the month's weather highlight was an Arctic outbreak in the second week of the month that produced the coldest reading in May (34°) since 1891.  May 2021, meanwhile, experienced one of the chilliest ends of any May, as May 28-31 tied May 1884 for the latest four-day streak with lows in the 40s.  This chilly ending was responsible for the coolest three-day Memorial Day weekend on record. 

 

Chart - 3 chilliest memorial day weekends

Despite the month's chilly ending, an extended period of above-average temperatures from May 15-27,  that was six degrees milder than average, kept the month close to average, temperature-wise.  And a very wet May 28-30, in which 2.57" was measured, balanced what, up until then, had been a dry May (these three wet days had as much rain as the previous six weeks).  So, when all was said and done, the month was very close to average on both the temperature and rainfall fronts (-0.3 degrees, and +0.40").

 

Before May's chilly and rainy close, six days in the 10-day period between May 18-27 had highs in the 80s.  This included highs of 89° and 88° during the weekend of 5/22 and 5/23; by contrast, the following weekend had highs of 51° on both days.  This reading (which was eight degrees colder than the average low for these two dates) tied a record for the coolest high on 5/29, and set a new record (by four degrees) on 5/30.

 

Besides the last four days of the month, which were 13 degrees cooler than average, there was an eight-day period from May 5-12 that was five degrees below average.  (However, the chilliest reading of the month, 42°, was on 5/1.)

 

Finally, the last six days of the month all had measurable precipitation, the longest rainy streak since one of eight days in May 2019 (5/10-17).  However, this year's streak had a touch more rainfall (2.68" vs. 2.56").

 

Here are recaps of the previous six Mays:

2020

2019

2018

2017

2016

2015

 

May 2001


April 2021 Weather Recap: Above Average Temperatures, Below Average Rainfall.

 

 Pink blossoms new york city

April 2021 featured ten days with highs of 70° or warmer, the first time April reported this many since 2010, and just the tenth time overall.   (The average number of such days in April is six.)  This above average number of warm days resulted in the month's average high being 2.5 degrees milder than average (its average low was 0.7 degrees above average).  Of the ten Aprils with ten or more highs of 70° or warmer, just four rank among the ten mildest Aprils.  This April ranked 22nd (out of 153). 

 

Chart - aprils with 10+ 70-deg highs
 

The month's  coldest temperature was 28° (on 4/2), which was the coldest reading in April in five years.  And although this April was significantly milder than April 2020 (which was 2.7 degrees colder than average), its coldest temperature was eight degrees colder.  The warmest reading was 85°, which is close to what the warmest reading in April has averaged since 2000 (last April was an exception, with a mildest reading of just 68°).   This reading came five weeks after the year's first reading in the 80s (82° on 3/26), and it was the warmest reading since Sept. 5.  

 

The month's warmest reading was on 4/28, but the most above-average period of the month was the seven days between April 4 and 10, when temperatures were eight degrees above average (high/low of 68°/49°).  In total, the month had twelve days that were five degrees or more above average, and five that were five degrees or more below average.  

 

Another highlight of the month occurred on 4/8 when the humidity dropped to 7% during the afternoon - the second lowest level this century.  Finally, April's rainfall of 2.69" was nearly two inches below average.  All but 0.05" fell between 4/11 and 4/30.

 

Here are April recaps of the past five years:

2020

2019

2018

2017

2016

 Park avenue in the spring


How "Back-Door" Cold Fronts Impact New York's Springtime Weather

 

Back door cold front

 

For the most part, cold fronts move from west to east in the Northeast, but, occasionally, chilly air arrives from the opposite direction.  When it does, this occurrence is known as a "back-door" cold front.   Because such a front's winds usually come off the ocean, this type of front is often associated with overcast skies (sometimes with drizzle); its east-northeasterly winds bring damp and chilly air. 

These incursions of chilly air that come from the opposite direction occur mostly in the springtime, when their cooling effect is enhanced by the wintertime water temperature of the Atlantic Ocean.  In terms of geographic reach, these fronts mostly impact New York City, the Jersey shore, and New England; only occasionally do they extend as far inland as Philadelphia, Baltimore, or DC.

What follows are 40 instances of the more impressive back-door fronts that have come down from the cold Atlantic.  As you'll read, six of the years had two notable back-door fronts.

 

East to west

June 4, 1895 - Winds shifted from the southwest to northeast during the afternoon, breaking a five-day heat wave (its record highs on June 1, 2 and 3 are still standing).  Between 3PM and 8PM, the temperature dropped from 91° to 64°.  The following day would be overcast, with temperatures stuck in the 60s. 

April 25, 1915 - This date experienced, perhaps, the greatest temperature swings of any in New York's weather history.  After the temperature soared from 47° shortly after midnight to 91° at 3:00 PM, winds shifted to the east-northeast, and the temperature plunged to 52° by midnight.  This was the result of a strong warm front moving through for about ten hours (9 AM-7 PM), then being displaced by a back door cold front.  No rain was produced by the passage of these fronts.  Two days later, a similar scenario unfolded.  After reaching 92° shortly before 4:30 on 4/27, a back-door front moved through a few hours later, and the temperature dropped to 54° by midnight.

April 1, 1917 - In the span of just eight hours, the temperature plummeted from 83° to 44° as a back-door cold front moved through, and winds shifted from the southwest to the northeast.  This was the warmest reading of the month, with the next reading in the 80s not occurring for another seven weeks.

March 19, 1918 - After a balmy high of 76° was reached at 3 PM (a record for the date that still stands), the wind shifted from the southwest to the northeast, and the temperature dropped like a rock, and was half that reading by midnight.

May 23, 1925 - After the high reached 91°, winds shifted from the southwest to northeast late in the afternoon, and by midnight the temperature had fallen to 59°; the temperature on the afternoon of 5/24 was only in the upper 40s.

July 1, 1933 - After a high in the low 90s, a severe thunderstorm from 8:30-10:30 PM dumped 2.17" of rain.  During the storm the temperature dropped from 88° to 72°, where it stayed for much of the next 24 hours.  And on 7/3, afternoon temperatures got no higher than the mid-60s.  

March 27, 1939 - Today's high/low of 73°/39° followed one of 72°/39° three days earlier.  However, while the low on 3/24 was in the pre-dawn hours, the low today was at midnight after winds shifted to the northeast in the PM hours.  And the following day had temperatures in a narrow range of 35°-40°.

April 25, 1939 - After rising from 53° at 4 AM to 86° for a few hours in the early afternoon, winds shifted to the northeast mid-afternoon and the temperature dropped back to 52° by 11 PM.  And then, three days later, the high would be only 46° (20 degrees below average).

July 4, 1941 - Just two days after a torrid high/low of 98°/78°, and winds out of the southwest, today was rainy, foggy and cool, with winds from out of the northeast, and a high/low of just 64°/62°.  Today's high would be July 4th's coolest until 1978.

 

Reverse
  

March 22, 1945 - In the midst of the very mild second half of March, today was an outlier as the high reached only 40° (the low was a seasonable 35°).  Winds were out of the northeast, skies were overcast and light showers fell throughout the day. 

April 13, 1955 - A chilly high of 46° came just two days after a high of 84°.  Skies were overcast and winds were from the northeast.

July 6, 1956 - Although yesterday was cool (high/low of 66°/58°), today was even cooler, as the high/low was just 61°/57° under gray skies and winds from out of the northeast.  These two unseasonably cool days followed consecutive days in the 90s.

June 1, 1959 - Today's chilly high of 64°, under mostly overcast skies, followed a five-day warm spell at the end of May that had highs averaging 87°.  Today's conditions were the result of a back-door cold front that moved in from New England last night. 

April 30, 1962 - After three days of summer-like warmth (highs of 91°-89°-80°), and winds from out of the southwest, winds shifted to the northeast after midnight and daytime temperatures were only in the mid-40s. 

April 19, 1964 - The day after the high reached 86°, a "back-door" cold front moved through, and by mid-afternoon the temperature dropped into the mid-50s.  (And on 4/21 the high would be just 44°.)

May 5, 1965 - The day after the high reached 90°, today's was 62°.  Winds were from a north-northeast-easterly direction.

April 28, 1966  - It was a dreary, raw, and damp day, with light rain in the morning.  With a high/low of only 42°/39°, today had the coldest mean temperature of the month.  On 4/26 the mercury dropped from 73° late in the afternoon, to 49° by midnight.  Then the high/low the next two days was 52°/40° and 42°/39°.  Winds were from out of the north-northeast.

April 20, 1972 - The temperature at 4 PM was a quite chilly 43°, a drop of 32 degrees since midnight, and forty-three degrees from yesterday afternoon's 4 PM reading of 86°.  This was a result of winds shifting to the northeast from dawn to dusk.

May 24, 1975 - Today's high of 93° (the Saturday of Memorial Day weekend) was the year's first reading in the 90s.  However, the heat was short lived as a cold front from the northeast moved through during the evening, dropping the temperature to 61° by midnight, and into the upper 50s by the following afternoon. 

 

Overcast

Aug. 11, 1979 - The day following a high of 95°, today's temperatures in the afternoon were only in the mid-60s after the wind shifted to the northeast during the morning.  The next day was equally cool (after a chilly AM low of 57°) - and  a wet one, as 1.68" of rain fell; this was on top of 0.87" of rain that fell the night of 8/11. 

March 29, 1985 - This was the third day in a row with exceedingly mild temperatures, and today was the warmest of the three with a high of 82°.  Then a back-door cold front moved through after dark, and by midnight the temperature was down to 55°, on its way to down to 46° by daybreak on the 30th (but still well above average).  

April 19, 1985 - After the temperature soared to 88°, a back-door cold front moved through during the evening, and the temperature was down to 51° the next morning.  Then the cool air retreated on the 21st, and after two more days with highs in the 80s, winds backed around and came from the east late in the afternoon on the 22nd, cooling the temperature down to 53° by midnight.  

March 30, 1989 - After the wind shifted to the northeast, the temperature fell all day, from 76° to 50°; the next day the high/low was 50°/41°, which wasn't far from seasonable, but it was quite a cool-down from 3/29's high of 82°.

March 14, 1990 - One day after Central Park recorded its earliest 80-degree reading on record, the warm front that delivered this extraordinary warmth retreated south of the area, as winds shifted to the northeast, and by afternoon, under a bank of clouds and fog, temperatures tumbled into the mid-40s, forty degrees colder than yesterday. 

May 23-25, 1992 - It was a Jekyll & Hyde Memorial Day weekend.  Saturday had mid-summer conditions, with a high of 92°.  Then a big change came on Sunday as a strong cold front pushed through in early afternoon, and temperatures plummeted from the low 80s to 45° by midnight.  Monday felt more like October, with overcast skies and a high of just 61°. 

April 12, 1996 - The high reached 80°, and then winds shifted to the northeast late in the afternoon, dropping the temperature to 55° by midnight, and 45° by daybreak on the 13th.

May 10, 2000 - After three days with highs in the 90s, winds shifted from the southwest to the east, bringing in much cooler air, and by daybreak today, the temperature was in the mid-50s, where it stayed for the rest of the day.  

June 12, 2000 - One month after a back-door cold front cooled down a hot spell, it was replicated today, with late afternoon temperatures in the upper 50s, and winds coming from the east-northeast, 24 hours after temperatures were in the low 90s.

 

Northeasterly winds
 

April 16, 2003 - After peaking at 88°, winds shifted to the northeast and by midnight the temperature was down to 51°.  And on the 17th temperatures fell slowly all day, and it was 36° at midnight.  Winds remained out of the east-northeast for the next six days.

May 14, 2004 - The day after the high reached 86°, the temperature was only in the low 60s in the early afternoon.  However, the wind shifted later in the day and temperatures were back into the mid-80s on 5/15.

April 20, 2006 - Today's high of 83° was the warmest reading of the month.  A back-door cold front moved through during the evening, and by midnight the mercury had fallen to the mid-50s, and the mercury was mostly in the 50s for much of the next day, and stuck in the 40s on 4/22 as a developing nor'easter moved up the coast .

April 29, 2009 - The day after the high reached 90° (and dropped 25 degrees by midnight after winds shifted to the north-northeast), the temperature was in the mid-50s by daybreak.

July 19, 2012 - After yesterday's extreme heat (high of 100°) and humidity, today's high, under mostly overcast skies, was just 76°.  Never before has there been such a drop-off in temperature the day following a reading in the triple digits.  The next day the temperature was around 70° during the afternoon. 

May 28, 2014 - One day after a sultry high of 86°, today was overcast, with afternoon temperatures only in the upper 50s.  The back-door cold front passed through after 10 PM, and the temperature quickly dropped into the low 60s, then gradually falling into the 50s by daybreak, where it stayed for the rest of the day. 

June 1, 2015 - After a week of temperatures in the summery mid-80s, today was 30 degrees colder, with periods of rain, drizzle and fog.  Today's high in the 50s was chillier than any day in May - the first time this has ever occurred.  And tomorrow would have similar conditions. 

May 20, 2017 - An early, three-day heat wave came to an end last night after a shift in wind direction.  Today's afternoon temperatures were in the low 60s, which was about 30° cooler than the highs of  the previous three days.

Nov. 4, 2017 - The day after temperatures were in the mid-70s, the temperature at daybreak today was nearly 30 degrees chillier, the result of a shift in the wind direction; afternoon temperatures were twenty degrees cooler.  On the positive side, skies were mostly clear.

April 8, 2019 - After peaking at 79° at 4 PM, winds shifted from west to northeast, and by midnight the temperature was down to 49°.

October 3, 2019 - The day after the mercury soared to 93° (the first reading in the 90s in October since 1941), winds shifted overnight to a northeasterly direction, and temperatures this afternoon were only in the mid-50s.  Light showers and drizzle fell throughout the day.

 

Overcast Skies_Brooklyn Bridge_RedHanded_StockF

 

 

 

 

 


March 2021 Weather Recap: Mild & Rainy Last Two Weeks

 Daffodils of march

 

The first week-and-a-half of March 2021 was exceedingly dry, with just 0.16" falling thru St. Patrick's Day.  (3/1 was the only day with rain.)  Then, in the last two weeks of the month, regular rainfalls returned, with 3.25" measured (more than 50% above average for that period).  The beginning of the month was also on the cold side, with temperatures four degrees colder than average through the 8th (the coldest day was 3/2, with a high/low of 33°/21°).   The rest of the month was six degrees above average, largely due to the last twelve days of the month, which were nine degrees milder than average (high/low of 64°/45°).  Overall, the month was 3.3 degrees above average, and was the 13th mildest March on record (March 2020 was eighth mildest).   The average high was 4.4 degrees above average; the average low was 2.3 above average.

 

The month's highlight was the record high of 82° on 3/26 – the first reading in the 80s in March since 1998 (and the eighth year in which the first 80+ occurred in March).  Besides this first reading in the 80s, March also had the year’s first readings in the 60s (3/9), and 70s (3/11).  This was just the third year in which all three occurrences happened in March, joining 1945 and 1977.

 

82 degrees

 

For the second year in a row, there was no measurable snow in March, just the second time this has happened; the first time was in 1945 and 1946.  And for just the fifth time, February, which was one of the snowiest, was bookended by a January and March with little snowfall.

 

Chart - snowy february bookended by snow-free months

There were eight days that were ten or more degrees milder than average (including 3/26's high of 82°, which was 29 degrees above average), and two others that were more than ten degrees colder than average.  14 days were five degrees or more above average (including eight in a row, from 3/21-3/28, that were seven or more degrees above average); eight were five degrees or more below average.

 

After back-to-back months with diurnal variations below ten degrees, March's was 16.6 degrees (average is 15.1).  Additionally, the range between the coldest and highest temperatures in March was 61 degrees (21° and 82°), the widest range since 2007, when it was 67 degrees (11° and 78°).  This was in contrast to January and February, both which had variations of only 37 degrees. (The greatest range in March is 72 degrees, which was in 1990, when the temperature extremes were 13° and 85°.) 

 

The month had fifteen days with humidity levels that dropped to 25% or lower at some point in the day (usually in the afternoon), with the lowest being 12% on 3/15 at 4:00 PM (and there were two other days with lowest humidity at 13%).  Finally, ten days had a peak wind gust of 35 mph or higher, with the peak gust at 44 mph, which was clocked during the evening of the 26th (the day with a high of 82°).   

 

Here are March recaps from the five previous years:

2020

2019

2018

2017

2016

 

 March_2021_iphone_calendar-scaled

 

 


Marches of 19th Century Were Far More Wintry Than They Are Today

The_Dakota_1880s

 

Of all the months of the year, March has warmed up the most since the 19th century (1869-1900).  While the average annual temperature so far this century (thru 2020) has been 3.6 degrees warmer than the average annual temperature in the late 19th century, March is 6.3 degrees warmer (April is next, at +5.2 degrees).  In the 19th century, March's average temperature was 36.5°, which would be considered quite cold for March of recent times (and more typical of what February's average is); the last time it was that cold in March was in 1984.  (March 2018 was a cold one by today's standards, with an average temperature of 40.1°). 

 

Eight of the coldest Marches on record are from the 19th century (and 18 of the 25 coldest).  Additionally, 16 current record lows in March are from the 19th century, as well as 15 record-low highs.  (One outlier is March 5, 1880, which had a record high that is still in place.)   Five of the six Marches with the the most highs of 32° or colder fell between 1875-1896.

 

Chart - cold cold march of 19th century

Eleven daily snowfall records established in March during that century still stand today.  The first, third and tenth snowiest Marches occurred in 1896, 1888 and 1890.  But of all of the snowstorms of one foot or more that the City has had, just one was from the 19th century - the Great Blizzard of 1888 that buried the City under 21".  (And for nearly 60 years it was the biggest snowstorm of all time; it's now the City's fourth greatest snowfall).

 

Blizzard of 1888 (2)

 

Ten of the thirty-two Marches had at least one reading in the single digits (for a total of 16).  Since then, just five other years have had it happen.  The last time was in 1967.  The frequency of such frigid March readings dropped from once every three years, to once every generation (24 years). 

 

Here are wintry highlights of the cold Marches of the late 19th century:

March 1, 1869 - High/low of 26°/4°.

March 14, 1870 - This was the fourteenth day in a row with highs of 40° or colder (the average high was 34°); six of the days had highs of 32° or colder.  9.5" of snow fell during this two-week period.  And March 17 was the sixteenth day in a row with a low temperature in the teens or 20s.

March 5, 1872 - This morning's low was 3°, the coldest reading ever experienced in March.  This was the second of three days in a row with lows in the single digits, the most of any March.  This is the third coldest March on record.

March 21, 1872 - High/low of 27°/14° on the first full day of spring. 

March 20, 1875 - An ice storm on the first day of spring dropped 0.54" of liquid precipitation in temperatures that were below freezing all day (high/low was 31°/22°).

March 23, 1875 - Five of the past six days had highs of 32° or colder.  Average high/low during these six days was 31°/18°.

March 18-19, 1876 - Lows of 9° on both days.

March 10, 1877 - The day after the mildest reading of the month (57°), the temperature at daybreak was 21°.  This was the first of eleven days in a row in which there were no highs milder than 40°; four days in a row would see lows in the teens (coldest reading was 10° on 3/19).  The average high/low during this very cold outbreak was 32°/22°.

March 19, 1877 - Yesterday's and today's frigid highs and lows of 26°/12° and 22°/10° were comparable to the Arctic cold experienced on the same two dates the previous year (30°/9° and 27°/9°). 

March 12, 1883 - This was the tenth day in a row with highs colder than 40°.  High/low during this time was 33°/17°.  Two snowfalls during this streak amounted to 5.5".

March 30, 1883 - A snowfall of 4.5" was the sixth snowfall of four inches or more this winter (none occurred in December).

March 1-5, 1884 - The month began with five days with highs of 30° or colder, with two reporting highs of 21°, and one, a high of 18°.  Average high/low during these days was 23°/12°.

March 30, 1884 - It was a very late date for a sub-freezing high temperature (31°) at a time of the month when the average high was around 50°.

March 18, 1885 - Today's low of 8° was the 18th in the single digits or colder this winter, breaking a tie with the winter of 1872-73 for most on record (later passed by the winter of 1918, which had 20 frigid lows).

March 24, 1885 - This was the eighth day in a row with lows in the teens or colder.  The average low during this stretch was just 13°.  (March 1885 is the second coldest on record).

March 21, 1887 - Today's high of 49° was the mildest reading this March - the only March with its mildest reading below 50° (it would happen a week later as well).  By comparison, January and February each had a reading in the low 60s.

March 29, 1887 - The temperature fell slowly throughout the day, from 29° shortly after midnight to 19° nearly 24 hours later.

March 2-25, 1888 - Thirteen of the days had highs of 35° or colder, and fourteen had lows in the teens or colder.

March 12, 1888 - The Blizzard of '88 (also known as the Great White Hurricane) roared into an unsuspecting New York during the morning and brought the City to a standstill for the next few days.  16.5" of snow fell today, with an additional 4.5" falling tomorrow into the early morning hours of the 14th.  This was New York's biggest snowstorm until Dec. 1947 (it's now ranked fourth).  In addition to the large amount of snow, the storm's danger was magnified by mountainous snow drifts created by winds that gusted between 45 and 55 mph, and extreme cold, as the temperature dropped from 33° to 8°.  

March 13, 1888 - A bit more snow (three inches) fell today from the blizzard that arrived yesterday, but what stood out  was the extreme cold (even by mid-winter standards), as the high/low was just 12°/6° - the second coldest day ever experienced in March (the high/low on March 5, 1872 was 10°/3°).  With gusty winds still prevalent, wind chills were below zero.  This was the fourth March in the 1872-1888 period to have two or three days with lows in the single digits; since then it's happened in just one other year (1916).

March 19, 1890 - A late-season snowfall of six inches was the largest accumulation of the winter, beating the snowfall of Dec. 14 by half an inch.  March 1891 had four snowfalls of three inches or more; they totaled 17.1", which is the tenth greatest accumulation for the month.

March 2, 1891 - The morning low of 9° was the coldest reading all winter.  This was similar to last year when the only reading in the single digits was also in March (7° on 3/7). 

March 18, 1892 - Snow that began falling late last night continued through this morning, accumulating eight inches (the 7.2" that fell today is the most to fall on 3/18).  This was the biggest snowfall of the winter (passing a six-inch snowfall on 1/16) and came in the midst of an unseasonably cold 12-day stretch (March 11-22),  in which the high low was a cold 34°/22°.

March 15-16, 1896 - Less than two weeks after a snowfall of ten inches on March 2, an even bigger snowstorm dumped a foot of snow.  (And in between these two storms, four inches fell on 3/12.)  It began early in the afternoon of the 15th, and by midnight 6.5" had accumulated; an additional 5.5" fell the next day through midday.  Then the snow changed to rain as the temperature rose into the mid-30s.  Then on 3/23, 4.5" fell, bringing the month's total snowfall to 30.5".  This would be Central Park's snowiest month until Feb. 2010, and is now ranked third (Jan. 2011 also had more).  High/lows were 28°/15° on 3/24 and 32°/23° on 3/27.

March 11-18, 1900 - Lows were 22° or colder for eight consecutive days.  The average for these days was 16°.

 

Womens muff

 

 


A Taste of Summer: The Year's First High of 80+

 First
Since 1980, the average date of the first reading of 80° or warmer is April 21 (a month later than the average date of the first reading of 70°+).  This is about a week earlier than 1900-1979, and two weeks earlier than the 1869-1899 period.  It's happened as early as March 13 (in 1990) and as late as June 7 (in 1924).  1918, 1927, and 2010 had their first reading of 80+ occur on the same date as each year's first high in the 90s. 

 

The average high temperature on the day before the first 80+ reading has been 70°, on the day of the first 80+, it's been 83°, and the high on the day following has averaged 74°. 

 

About one-third of the years have had a day of 80° or warmer on the day following the first 80+, but 16 years didn't have their second high of 80°+ for four weeks or more.  The greatest number of days to elapse before the second 80+ reading was 57 in 1928 (April 6-June 1).  The most recent lengthy hiatus was 41 days in 2013 (April 10-May 20).

 

Eight years have had their first 80+ high in March.  The first time it happened was in 1921, the most recent occurrence was 100 years later, in 2021.  Meanwhile, a first 80+ in June has occurred just once (1924).

 

Chart - earliest and latest first 80

 

On the day with the first high of 80° or warmer, the diurnal variation has averaged 27 degrees (this compares to a 14-degree variation for any day of the year).  The  greatest variation was 43 degrees in 1929, when the high/low was 89°/46°.   The smallest variation was 16 degrees in 1908 (81°/65°).

 

Chart - greatest diurnal variation on day of first 80
 

The chilliest low on the day of  the first 80+ reading was 43° in 1936 and, again, in 1990.  The warmest low was 68° in 1898.  The chilliest day-before high was 49°, in 1977.  The chilliest day-after high was 50° in 1921, and 51° in 1939.

 

29 years (about once every five years) had a warmer reading on the day after the first 80+ reading.  The warmest day-after reading was 93° in 1988.   The last time the day-after was warmer was in 2009, when the  high was 92° (the first 80+ reading that year was 88°).  The warmest day-before reading was 79°, which has happened in four years, most recently in 1955.  (And ten other years had a day-before high of 78°.)

 

April 19 is the date that's had the most first 80+ occurrences - in ten years.  And it's happened in seven years on April 25.   The most consecutive years to have the first 80+ occur in May is six, from 1873-1878. 

 

There have been six pairs of years in which the date of the first 80+ was the same:

> April 18, in 2015 and 2016

> April 15, in 2002 and 2003

> April 19, in 1972 and 1973

> April 26, in 1969 and 1970

> May 16, 1931 and 1932 (and in 1933, the date was 5/15)

> April 19, in 1914 and 1915

 

There have been fiver pairs of years in which the dates of the first 80+ were at opposite ends of the early/late spectrum.

> 1997 - May 19/ 1998 - March 27

> 1988 - May 23/ 1989 - March 28

> 1984 - May 23/1985 - March 29

> 1945 - March 20/ 1946 - May 25

> 1920 - May 28/ 1921 - March 21

 

Finally, measurable rain has fallen on the day of the first 80+ reading in 20% of the years (similar to the day of the first reading of 70+).  The biggest rainfall on this date was 0.67" in 1984 (May 23) as afternoon thunderstorms moved in after the temperature peaked at 81°; the second most was 0.60" in 1951 (4/29).

  80 plus

 

 


2021's Weather Happenings

 

 2021JANUARY

January 26 - The 0.1" of snow that fell was the first measurable snow since the 10.4" snowstorm of Dec. 16-17, nearly six weeks ago.  Today's high and low were just three degrees apart (34°/31°).

January 31 - Until this evening, the month was set to become one of the five least snowy Januarys on record, with just 0.1" measured.  However, the opening volley of snow, from a snowstorm that would bury the City tomorrow, moved in this evening, and by midnight two inches had accumulated.  This was the most snow to fall on this date since 1898 (when five inches piled up).  The 2.1" that fell this month made this the third January in a row with well below-average snowfall (Jan. 2019 had 1.1", Jan. 2020 had 2.3").

 

FEBRUARY

February 1 - A monster snowstorm that moved in last night buried the City today, and largely exited by daybreak the following day.  In total, 17.4” of snow was measured, with 14.8” of it piling up today.  The rate of snowfall was greatest from mid-morning thru mid-afternoon.  The temperature rose from 22° just after midnight to 34° in the early evening, when the snow mixed with freezing rain and drizzle, which put a stop to further significant accumulation.  15”-24” accumulations were common throughout the region.  Besides the snow, high winds were also an issue, gusting between 30-40 mph in Central Park.  

With this snowstorm, the winter became New York’s twelfth with two or more snowfalls of ten inches or more (the first one was on Dec. 16-17, when 10.4” fell).  This was New York’s biggest snowfall in five years (when New York experienced its biggest snowfall of all-time), and tied for fifteenth greatest accumulation on record (with Feb. 3-4, 1961). 

February 7 - Today was Super Bowl Sunday, and up until this year, the most snow to fall on this occasion was 1.5" in 2000.  That amount was easily eclipsed today, when a fast moving storm dropped 4.5" from mid-morning thru late afternoon (Central Park was low-man on the totem pole as most surrounding areas had six to eight inches).  It was a wet snow, that began falling when the temperature was 37°, with the temperature not reaching 32° until early afternoon.  This brought the month's snowfall to 19.9".

February 16 - While the Southern Plains, Midwest and Ohio Valley were subjected to severe cold, snow and ice, New York basked in mild temperatures and sunny skies during the afternoon as the temperature rose to 51°, the first reading in the 50s since Jan. 2 (when the high was also 51°).  This respite broke a nine-day streak with colder than average temperatures (but below average temperatures would return the next day).  Before the sun came out a period of heavy rain fell before sunrise, amounting to 0.82". 

 

MARCH

March 5 - Sunny and cold (high/low of 37°/23°) with very low humidity in the afternoon, which bottomed out at 17% between 3-4:00.  This was the lowest humidity reported in Central Park since the first week of May last year.

March 9 - Under fair skies, the temperature rose into the 60s for the first time this year, about five weeks later than the typical date for this occurrence.  The day's high of 64° was the mildest reading since Thanksgiving Day (when the high was 65°).  Also, the air was also quite dry, dropping to 23% during the afternoon.

March 12 - One week after the humidity dropped to 17%, it was even lower this afternoon, bottoming out at 13% during mid-afternoon.  The last time Central Park reported a level lower than this was on today's date in 2016, when it was 12%.  Today's humidity was at 20% or lower for 11 consecutive hours.  Besides the low humidity, the day also featured very mild temperatures, with a high of 68°.  The day also had the year's first low in the 50s.

March 15 - Afternoon humidity fell to 12% during the afternoon, the lowest reported in Central Park since March 2016.  Additionally, dew points were extraordinary low, dropping below zero a few hours before daybreak and remaining sub-zero thru the wee hours of 3/16.  (And during the afternoon they were below -10°.)  Today was also the 14th day in a row with no measurable precipitation, the longest streak of dry weather since last June.

March 17 - This was the 16th day in a row with no measurable precipitation, matching last year's longest dry streak in September; these are the longest dry spells since an 18-day streak in the fall of 2017.  

March 18 - After one of the driest first halves of March on record (0.16" was measured), light rain that began at around 9 AM continued for the rest of the day.  The rain amounted to 0.60", and was the first measurable precipitation since 3/1.   Temperatures were mostly stuck in the mid-40s.  

March 26 - Between noon and 2:00 winds shifted from the southeast to the southwest and the temperature jumped from the low 60s to low 80s.  Today’s high of 82°, a record for the date, and the first reading in the 80s in March since 1998.   This early jump into summer was a surprise since the predicted high was in the low 70s.  This became the eighth year to have its first reading of 80+ in March, and the fourth earliest date (after March 13, 1990; March 20, 1945, and March 21, 1921).  Interestingly, this early first 80 followed last summer’s early last 80, which happened on 9/10.

 

APRIL

1 - Temperatures were in the chilly 44°-50° range during the Home Opener of the Yankees, made even chillier by blustery conditions, as winds gusted between 25-30 mph.  The only positive aspect of the day (the Yankees lost to Toronto in 10 innings) was that the sun began to break through the overcast skies during the second half of the game. 

4 - Despite starting out overcast, it turned into a beautiful Easter Sunday as the skies cleared late in the morning, and the temperature rose to 65°.   The air was also quite dry, with the relative humidity falling to 23% late in the afternoon.  

6 - On a stunningly beautiful day, the high reached 70° and the humidity dropped to 7% late in the afternoon – the lowest humidity level reported in Central Park since 2007 (6% on March 30).  This followed 13% humidity yesterday afternoon (and March had a day with 12% humidity, and two others with 13%).  For five hours the humidity stayed below 10% (and dew points were in the 3°-5° range).

8 -  Skies were sunny, the mercury rose to 70°, and the Mets came from behind in the bottom of the ninth inning to win their home opener against Miami, 3-2.  As so often happens, the Mets had better home-opener weather than the Yankees, as skies were brighter, and it was about twenty degrees warmer.  

28 - In a span of ten hours the mercury shot from 52° (at 4AM) to 85° (2PM), the warmest reading since Sept. 5 (when the high also reached 85°).   Yesterday's high, by contrast, was a slightly below average 64°.  Today's diurnal variation of 33 degrees was the greatest since Jan. 13, 2018, when it was 39 degrees (high/low of 58°/19°).  This was the year's second reading in the 80s, occurring five weeks after the first. 

 

MAY

18 - This morning's low of 60° was the first low in the 60s this year, the latest date for this occurrence since 2003 (when it happened on 5/30).  Under partly cloudy skies, the high rose to 82°.  (Last year's first 60+ low was also late, occurring on 5/15.)  Since 1980, the typical date of the first 60+ low has been 5/2. 

26 - It was a warm and sticky day.  Temperatures varied greatly in the area, as the high reached 86° in Central Park (and at LaGuardia), while Kennedy Airport was just 75°, and Newark Airport's high was 94° (its fourth reading in the 90s this month; CPK had none).  Rain showers in the early evening and around midnight produced 0.07" of rain, the most in two-and-a-half-weeks.  (Because severe thunderstorms were predicted, the Mets and Yankees postponed their games, but the storms didn't materialize.)   

28 - Morning sunshine gave way to overcast skies in the afternoon, and rain moved in after 4:00 (just as the Memorial Day weekend was getting underway).  The rain became steady and wind-swept after dark (peak gust was 36 mph at Central Park), and amounted to 1.22", which was a record amount for the date (the rain continued thru the morning of 5/29).  The temperature dropped from 69° in the early afternoon to 49° less than twelve hours later.  This was the latest date for a reading in the 40s since 2000 (when it happened on 6/7). 

30 - Today’s very cool high/low of 51°/47° was identical to yesterday’s.  But while yesterday’s high tied for the coolest high on 5/29, today’s high broke the record by four degrees.  These highs were 24 degrees below average (and more typical of the first day of spring).  Today’s and yesterday’s high/low were the chilliest back-to-back days in late May since May 25-26, 1967 (46°/42° and 53°/46°).  And also like yesterday, there were gray skies and rain, with 0.89" falling from sunrise to mid-afternoon.  The 48-hour rainfall total (from two storm systems, beginning late afternoon on 5/28) was 2.57”, which was nearly 50% more than what fell between May 1-27 (1.77”). 

Coincidentally, May 29-30 of last year had the same, but much warmer, high/low:  81°/67°.  This is just the second time that the same dates in  consecutive years had temperature "twins" (the other instance was in 1897 ad 1898 on July 27-28).

31 - Today, Memorial Day, was the fourth day in a row with a low in the 40s, tying May 1884 for the latest streak of this many days.  (However, 1884's streak was chillier: 48°-43°-42°-48° vs. this year's 49°-47°-47°-49°.   This was the chilliest three-day Memorial Day weekend on record.  Although Memorial Day was eight degrees cooler than average (high/low of 70°/49°), it felt summer-like compared to Saturday and Sunday, which were overcast, rainy and very cool, with each day having a high/low of just 51°/47°. 

 

JUNE

6 - Central Park had its first reading in the 90s this year (92°), as well its first low in the 70s (76°) -  the first time since 2013 that both occurred on the same date.  Today's first low in the 70s fell on the same date as last year's; the last time this happened was in 1988 and 1989 (when the date was 5/30).  This weekend's highs of 89°/91°, and those of two weeks ago, 89°/88°, were in very stark contrast to last weekend's highs of 51°/51° (Memorial Day weekend). 

9 - With a high of 90°, this was the fourth, and last, day of a four-day heat wave.  (And the day before the heat wave started, the high reached 89°.)  This was the first heat wave of this length in June since 2008.  And although that heat wave's average high was significantly hotter (95° vs. 91°), this June's heat wave had low temperatures that were significantly warmer (75° vs 70°).  It was also very humid, with dew points largely in the 68°-72° range, producing afternoon heat indices in the mid-90s.  With four days in the 90s through 6/9, this was the earliest for that number of days since 2000, when the fourth such reading occurred on 6/2 (ironically, that year would have only seven in total). 

12 - Today's high/low of 69°/62° was the same as yesterday's (and skies were overcast both days).  This followed another pair of days with the same high/low just just a few days earlier, as June 8 and 9 each had a high/low of 90°/72°.   (And June 6 and 7 missed being "twin" days by one degree, as the highs/lows were 92°/76° and 91°/76°).   Two weeks earlier, on Memorial Day weekend, the high/low on both days was 51°/47°.  (A typical years has two or three of these temperature twins.) 

23 - Today's low of 55° was the chilliest reading of the month (but far from 1918's record of 49°), and the coolest reading this late in June since 1995, when a low of 54° occurred on June 28.

27 - For the second year in a row (a first), the high reached 90° on Pride Sunday.  And with an afternoon dew point in the 70°-71° range, the heat index reached 96°.  Skies were a mix of sun and clouds, which cleared as evening approached.

30 - It was scorching-hot day, with a high of 98°, the hottest reading in Central Park since the summer of 2013, and the hottest high temperature in June since 1994 (also 98°).  This was the fourth day in a row with a high in the 90s (the other days had highs of 90°, 92°, and 95°), joining another four-day heat wave earlier in the month.  This was just the second June with two heat waves of four days or more (the other was in 1943, which is the hottest June on record).  Cooling showers moved through after 8:30, dropping the temperature to 73° (the morning low had been a sultry 80°).  The rain kept this from being the second June in a row with less than two inches of rain, and the amount that fell (0.65", much of it between 10-11 PM) was the greatest daily amount of the month.

 

JULY

3 - Three days after June had its hottest reading since 1994, today's low of 59° was the first in the 50s in July since 2009.  And under overcast skies the temperature rose only to 66°, which was three degrees cooler than the average low for the date.  This was the first high in the 60s in July since 2013, and the coolest July high since 2005.  Furthermore, today's mean temperature of 62.5° was the coolest in July since July 12, 1990, which had the same mean (high/low of 67°/58).  Finally, today was  the fourth day in a row with measurable rain.  Today's 0.34", which fell mostly during heavy showers shortly after daybreak, brought the 4-day total to 2.56", which was nearly as much as what fell during the entire month of June (2.62").   

4 - This morning’s refreshing low of 60° (shortly after midnight) was the coolest on the holiday since 1992 (when it was also 60°).  Only ten other 4th of Julys have had a cooler low.   (In the years since 2000 the average low had been 70°.)  The high of 79° was the coolest in six years, but after last week's four-day heat wave, today’s temperatures were delightful for spending time outdoors celebrating the nation’s birthday.  

6 - After a steamy high of 92° (the third year in a row with a high in the 90s on this date), thunderstorms between 6-11 PM dropped the temperature some 20 degrees.  (Winds gusted close to 60 mph at LaGuardia and Newark airports, and a 37 mph gust was clocked at Central Park.)   This evening's rainfall amounted to 0.55" and brought the seven-day total to 3.11". 

8 - After sunny skies predominated through early afternoon, 2.27" of rain flooded the City between 4:30-7 PM, setting a rainfall record for the date (the previous record was from 1899).  Much of the rain fell during a severe thunderstorm that produced torrential rain during the evening rush hour, dumping 1.56" between 5-6 PM.  NYC was the bullseye for this storm, as the area's three major airports had much less, with LaGuardia reporting 0.95",  JFK getting 0.32", and Newark seeing just 0.09".  Today's rain was the greatest daily amount to fall in Central Park since July 10 of last year, when 2.54" was measured as tropical storm Fay passed by (also a record amount).

9 - 12 hours after the City was flooded by a torrential downpour during yesterday’s evening rush hour, heavy rain from the remnants of hurricane Elsa made this morning's commute a challenge.  1.79” of rain fell this morning, largely between 3-9AM.  (Elsa brought significantly more rain over Long Island, largely in the 3-4” range.)  Then tonight, between 10:30-11:00, one more heavy shower moved through, adding 0.27" to the day's total.  And like yesterday's amount, today's 2.06" was a record for the date (easily breaking the old record of 1.09"). 

In the past ten days (Since 6/30), seven days of rain have totaled 7.44”, equal to what fell in the previous eleven weeks.  Between yesterday afternoon and later this morning, 4.06” of rain was measured in Central Park.  This was the greatest 24-hour total since April 30, 2014, when 4.97” poured down.

12 - In the wee hours of the morning, Central Park had its third one-hour deluge of an inch or more in the past five days.  The 1.42” that poured down, mostly between 2:15-3:15, brought the month’s rainfall to 8.49”, making this the wettest July since 1975, and the 7th wettest July (with 19 days to go).  The rest of the day was rain-free, but oppressive, with dew points in the 72° to 75° range.  This produced a heat index in the low 90s (the afternoon high was 86°).

13 - After getting soaked by six inches of rain in the past five days, today was rain free, but gray skies/low clouds predominated, and the air was thick with humidity.  This combination kept the temperature from rising much, as the high of 72° was just three degrees warmer than the low.  But despite afternoon temperatures that were 13 degrees below average, the air wasn't refreshingly cool since daytime humidity was in the 85%-90% range.

26 - For the second day in a row there was a heavy period of pre-dawn showers; yesterday’s downpour produced 0.49”, today’s amounted to 0.78”.  Today’s amount brought July’s rainfall over ten inches, joining 26 other months that have exceeded the amount (out of 1,831+ months, going back to 1869).  This was the first time a month had ten inches or more of precipitation since June 2013, and the most in any month since August 2011’s 18.95” (rainiest month on record in Central Park).  The 10.48” that has fallen so far this month made it the third wettest July on record.

29 - Three days after July became the 27th month to have 10+ inches of rain, today it became the 15th to have more than 11+ inches, as a little under a half-inch fell during thunderstorms between 5-9 PM.  The City escaped turbulent conditions that affected parts of NJ and eastern PA, where a number of tornadoes touched down.  And the thunderstorms that moved through the City weakened as they moved over Manhattan, reducing the predicted amounts of rain.  This was the 18th day that measurable rain fell in July; only July 1871 had more days (20).  However, July 2021 had twice as much rain.

 

AUGUST

21 - A plume of tropical moisture associated with hurricane Henri (still hundreds of miles to the southeast of NYC) moved in after 8 PM, flooding the City with 4.45" of rain, a record for the date (much of it fell between 10 PM-midnight).  Today’s rainfall was three times the amount that fell in the first 20 days of the month (1.46”).  NYC appeared to be the bulls-eye for the torrential rain as La Guardia, JFK, and Newark had much less (but still significant) amounts of  2.46", 2.13", and 1.28", respectively.  The rain that poured down tonight was the most to fall on a calendar date in Central Park since April 30, 2014, when 4.97" poured down.

Despite the fact that the amount of rain that fell to break the 1888 record of 4.19", fell between midnight-1 AM (0.36") on 8/22, this is because the NWS uses Standard Time year-round for its daily observations rather than Daylight Saving Time during the spring and summer months; therefore, midnight- 1 AM Daily Saving Time is actually 11P-midnight Standard Time.

22 - A second round of heavy rain from tropical storm Henri began shortly after daybreak, as the storm headed to Rhode Island, where it made landfall early this afternoon.  Although today’s soaking rain wasn’t torrential, like it was last night (when 4.45” poured down), the 2.67” that fell today was enough to establish a record for the second day in a row.  (This followed back-to-back record rainfalls last month, on 7/8 and 7/9).  The rain fell heaviest between 2-5 PM, when 1.49" was measured. 

The 24-hour rainfall total of 7.04” (between 8 PM yesterday and 8 PM today) was the greatest amount to fall in this amount of time since April 2007, when 7.80” fell between 2AM on 4/15 and  2AM on 4/16.  Although Henri produced record rainfall in NYC, one saving grace was that that there were no gusty winds to contend with.      

23 - The last spasms of what was once hurricane Henri produced 1.07” of rain shortly before daybreak (when 0.93” fell), and during lunchtime (when the dew point rose to 75°, the peak reading during Henri's "visit").  This was the third day in a row to have more than an inch of rain, just the tenth time this has happened, and the first time since Oct. 12-14, 2005.  In total, 8.19” of rain fell.  This brought August’s rainfall to 9.65”, and July-August’s total over 20 inches – just the fifth time a pair of consecutive months has received this much rain.  Finally, August 2021 is now the fifth rainiest August on record (following July, which was the third rainiest).

27 - It was hot and humid, with a high of 93° (the heat index reached 102°), the third day in a row with a high in the 90s.  Then a thunderstorm moved through late in the afternoon and produced enough rain in Central Park (0.67”, almost all of which fell between 5:15-5:45 PM) to bring August’s rainfall over ten inches.  This was after July had 11.09" of rain, making July-August just the second time consecutive months had 10 inches or more of rain.  (The other time, March-April 1983, has been disputed because the rain gauge in CPK was broken for a good portion of the year).  Just before the skies opened up, the dew point rose to 77°, which was the highest of the summer.  Interestingly, no rain fell in my Greenwich Village neighborhood (just thunder), which is about three miles south of Central Park (while LaGuardia Airport had twice as much rain as the Park).

 

SEPTEMBER

1 - Although Hurricane Ida, which made landfall in Louisiana four days ago as a category 4 storm, had weakened to a tropical depression by the time it made its way to the Mid-Atlantic, what energy remained packed quite a punch as New York was flooded by extreme rainfall and lashed by tropical storm-force winds (causing more disruptions than tropical storm Henri did less than two weeks ago).  After a first round of moisture brought light showers shortly after sunrise, there was a lull until 5 PM when heavy rain moved in, becoming torrential a few hours later.  By midnight, 7.13" had been measured in Central Park – comparable to seven weeks of rain, and two-and-a-half inches more than a typical September sees in its entirety. 

At its most intense, between 9-10 PM, more than three inches poured down.  Because of this excessive rate of rainfall, the National Weather Service, for the first time, issued a Flash Flood Emergency for NYC, and subway service was suspended throughout the City.   Shockingly, 13 residents in Brooklyn and Queens died from flood-related causes.  Unlike Henri, which wasn’t a wind producer, Ida’s visit was accompanied by winds that gusted between 35-50 mph.  

Between Aug. 21 (when Henri moved in) and today, 15.99" of rain was measured in Central Park.  And between June 30 and today, 29.19" fell.  By comparison, average rainfall during this nine-week period is around 9.30".

23-24 - Chilly air moving into air that was warm and humid (dew points were around 70°) produced periods of heavy rain that began in the evening and continued until sunrise the following day.  2.03” fell in total (1.36” of it today), with much of it, 0.86”, pouring down between 7-8 PM (and 0.51” between 3-5 AM).  The rainstorm brought the month’s total to 9.76”, making this the rainiest September since 2004 (11.51”), and the sixth wettest on record (following July and August, which were the third and fifth wettest of their respective months).

This was also the first time on record that three months in a row had more than nine inches of rain (totaling a little more than 31 inches).  With a little more than three months left to 2021, 51.69" of precipitation has been measured, which is more than what an entire year averages (a little under 50 inches).