Monthly Recap Feed

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


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

 

 


February 2021 Recap: New York Trudges Through One of Snowiest Februarys On Record

 

Feb 1 snowstorm nbc nightly news

 

February 2021 was 1.1 degrees colder than average, and the eighth snowiest February on record, with 26.0” measured.  More than half of the snow fell on Feb. 1, when 14.8” piled up (in total, the storm produced 17.4”).  This was the largest accumulation ever reported on the first day of February.  Another highlight of the month was the severe Arctic outbreak in the middle of the month that plunged Texas, the southern Plains, Midwest and Ohio Valley into the deep-freeze, but barely brushed New York.  Although the month was colder than average, the coldest reading was just 17° (the month's only reading in the teens).  The month's colder than average status was driven by the average high, which was 2.7 degrees colder than average; meanwhile, the average low was slightly above average (+0.5 degree).  Finally, with 5.13" of precipitation, the month was among the ten wettest Februarys since 1930 (and 21st wettest going back to 1869).

 

This was New York's coldest February since 2015 and the first colder-than-average month since May 2020. It was also the first year since 2015 in which neither January or February had any readings of 60° or milder.  The 15-day period between Feb. 7 and 21 was five degrees colder than average (high/low of 35°/25°), with all but one of the days colder than average (10.2" of snow fell during this period).  Temperatures rebounded during the last six days of the month, and were six degrees milder than average (high/low of 48°/38°); temperatures were above freezing for the entire period.

 

Like January, there was just a 37-degree range between February's coldest and mildest readings (17° and 54° in February, 14° and 51° in January).  Since 1950, the typical range has been 49 degrees (11° and 60°); during these year just six other Februarys have had a smaller range, most recently in 2010 (29 degrees).  Meanwhile, the month's average diurnal variation (the difference between the high and low temperature) was just 9.5 degrees (February's average is 13.5 degrees), making it just the fourth February with a diurnal variation less than 10 degrees.  (The others were in 2010, 1969 and 1869.)  This was only the second Jan./Feb. in which both months had diurnal variations less than ten degrees.  (The other time it happened was in 1869.)  Jan./Feb. 2021’s diurnal variation of 9.7 degrees beat out 1869's by 0.1 degree for smallest variation.

 

Chart - smallest diurnal variation jan_feb

 

This winter’s December-February combo was the ninth snowiest on record.  It joined four other pairs from this century (the other five happened before the winter of 1962).

 

Chart - snowiest dec_feb combinatons

 

February 2021 joined sixteen other Februarys that had 20 inches or more of snow.  It was milder than all but two of them (February 1983 and 2006).

 

Chart - mildest februarys with 20 inches of snow

 

Looking at December thru March, February 2021 ranks as the fifteenth snowiest month, just 0.1" behind Feb. 2003, Jan. 1996 and Feb. 1894.  This February's hefty snow accumulation was quite a contrast to last February, which saw just a trace.

 

Chart - snowy feb preceded by no snow feb

Here are other February recaps:

2020

2019

2018

2017

2015

 

 


January 2021 Weather Recap - Winter Makes Late Appearance

Late bloomer

 

If you're not a "winter person", then the first three weeks of January 2021 were tolerable, as temperatures were six degrees above average (with every day but two above average), and there was no snow (average high/low was 43°/33°).  Then, the jet stream shifted, and the last nine days of the month were five degrees colder than average (high/low of 33°/22°).  On the last day of the month conditions became even more wintry.  Up until the 31st, it appeared the month was going to be among the five least snowy Januarys on record, as just 0.1" had fallen.  But then, the opening volley of snow from a snowstorm that would bury the City on Feb. 1 dropped two inches between 6:00 and midnight - the most snow to fall on this date since 1898. 

 

Despite being 2.2 degrees above average, January's mildest reading was just 51° (on Jan. 2).  This was, by far, the mildest January to have its warmest reading this cool.  Previous Januarys with mildest readings that were either 50°, 51°, or 52°, had an average monthly temperature of 28.9°, which is is 5.9 degrees colder than January 2021 (34.8°). 

 

The coldest day of the month was the 29th, with a high/low of 25°/14° (thirteen degrees colder than average).  This was the coldest day in two years (since a high/low of 21°/11° on Feb. 1, 2019).  

 

With just 2.1" measured, this was the third consecutive January with snowfall that was well below average (January 2019, had 1.1", January 2020 had 2.3").  It was the fifth string of low-snow Januarys.

 

Chart - minimal snow consecutive januarys

 

With an average high of 39.7°, and an average low of 29.8°, January's diurnal variation was just 9.9 degrees, making this just the third January whose average high and low was less than ten degrees apart.  The two others were in 2017 and 1869 (variations of 9.4 and 9.8 degrees, respectively).  This narrow diurnal variation was largely due to the month's average low being notably more above average than the average high (+2.9 degrees vs. +1.4 degrees, respectively).

 

Here are previous January recaps:

2020

2019

2018

2017

2016

2015

2014

 

 

 


December 2020 Weather Recap: Two Storms Grab Headlines

Janice huff wnbc dec2020

 

The lasting memory of December 2020 will no doubt be the snowstorm of Dec. 16-17.  The 10.5" of snow that piled up was the biggest snowfall in December since 2010 and the thirteenth December snowfall of 10"+.  Another highlight was the intense rainstorm that blew through the City on Christmas morning.  The month was 1.7 degrees above average - the City's 34th mildest December (since 1869).  But despite being milder than average it had more days with highs of 32° or colder than all of last winter (four vs. three).  Additionally, the big snowstorm produced more than twice as much snow as the previous winter (10.5" vs. 4.8").

 

  • Five days had highs of 55° or milder while six days had lows of 25° or colder.  There were three days with highs in the low 60s, evenly spaced, on 12/1 (62°), 12/13 (62°) and 12/25 (61°).  Five of the six days with lows of 25° or colder had lows of 24° (the outlier was the reading of 20° on 12/19).
  • The mildest and coldest periods of December occurred during the fifteen-day period from Dec. 11 thru Dec. 25.

 

Chart - december 2020 coldest_mildest periods

 

  • Christmas Day's high of 61° (before sunrise) made it the eighth Christmas with a high in the 60s, and the 0.92" of rain that fell was the third greatest amount on the holiday.  After the high was reached the temperature fell steadily throughout the day and was down to 29° by midnight.  This 32-degree drop was the greatest of any calendar date in 2020.
  • Although the month was on the mild side, five Decembers in the past ten years were even milder.

 

Chart - mildest decembers since 2011

 

  • December 2020 was the 29th December with ten or more inches of snow (nearly 20% of all Decembers).  However, it was the second mildest December (after Dec. 1912) to have this much snow.  Although their average temperatures weren't quite as mild as this December, the Decembers of 1948, 1959 and 2003 had considerably more snow (25.3", 15.8" and 19.8", respectively).

 

Chart - snowy mild decembers

 

  • Much of the month's 4.61" of precipitation (0.61" above average) fell from three storm systems, all which produced more than an inch of precipitation:  1.13" on Dec. 4-5; 1.52" on Dec. 16-17; and 1.16" on Dec. 24-25.
  • Finally, similar to November, December had a lot of days with gusty winds, with Central Park having nine days with a peak gust of 33 mph or more.  The peak gust of 47 mph occurred early Christmas morning.

 

Chart - December peak wind gusts

 Snowstorm of dec 1617 2020

 

Other December recaps:

2019

2018

2017

2016

2015

 

 

 


November 2020 Reigns As Mildest November On Record

WashSqPk_Nov2020

 

November 2020 was 5.2 degrees warmer than average and became the warmest November on record, supplanting November 2015 by 0.2 degrees.  Sixteen days had highs in the 60s or 70s (one fewer than the 1931 record).  What stood out was a streak of six days with highs in the 70s from Nov. 6-11, the longest such streak to occur in November.  (And the seven days between Nov. 4-10 all had clear or mostly sunny skies.) Conditions on Thanksgiving Day were noteworthy as well.  Although the high of 65° wasn't the warmest on record (it tied for third warmest), its low of 55° was.  (Just two years ago Thanksgiving Day had a high/low of 28°/17°.)  It was also one the seventh rainiest Thanksgiving, with 0.79" falling in the morning.  What follows are a few other observations:

 

  • Typically, November is 5.4 degrees cooler than April.  This year, however, it was 2.4 degrees milder and became just the tenth November to be milder than April.  (Nov. 1975 was warmer than April by the greatest margin, +4.4 degrees.)
  • The eight-day period between Nov. 5-12 was 14 degrees above average.  The rest of the month was two degrees above average.  These 22 days included four days that were ten or more degrees above average and two other days that were ten or more below average.  Overall the month had nineteen days that were five or more degrees above average.
  • At 3.99", the month's rainfall was an average amount, and that was thanks to a rainstorm that brought 0.98" on the last day of the month.  It was also the month's biggest rainstorm.  This storm was accompanied by gusty winds.  The peak gust was 35 mph, which was the seventh day of the month to report a peak gust of 30 mph or greater (the area's three major airports, LGA, JFK and EWR had gusts of 30 mph+ on ten, twelve and nine days, respectively, and their peak gusts were much higher).

 

Chart - wind gusts nov 2020 

  • The three warmest Novembers have all occurred in the 21st century, as well as half of the ten warmest and half of the top 12.
  • Despite being the warmest November on record, this November is tied with Nov. 2011 for warmest average high and tied for fourth mildest average low.  Additionally, Nov. 2020 had two days with sub-freezing low temperatures (both were 30°) while half of the ten mildest Novembers had coldest readings that were above freezing.
  • Besides this November, Nov. 1994 and Nov. 1975 also had six days in the 70s (but they weren't consecutive).  But they rank second behind Nov. 1953, which had seven such days.

 
 Chart - 10 mildest novembers2

Here are five previous November recaps:

2019

2018

2017

2016

2015

 

 Nov 7 high rises on hudson

 

 


October 2020 Weather Recap: 'Mother Nature' Dresses Up as 'Jack Frost' for Halloween

New york in fall 2020

 

October 2020 was slightly milder and wetter than average in New York.  The month's first week-and-a-half was uneventful, with just 0.06" of rain.  Then three significant rain events soaked the City, each bringing more than an inch of rain: 1.30" fell on 10/12-13; 1.36" on 10/17 and 2.17" on 10/29-30.  The first and third rainmakers were from remnants of hurricanes Delta and Zeta.  The month ended up with 5.05" of rain, 0.65" above average.  Overall, the month was one degree above average, making it the 11th October in a row that was milder than average.  The low was nearly two degrees above average while the high was just about average (+0.1 degree). 

 

Until the end of the month the chilliest reading had been 44°, which would have been one of the mildest readings for this distinction in October (October 1946's and 1971's coolest reading was 45°; October 2007's was 44°; last October's was 43°).  But then a shot of Arctic air followed the rainstorm of 10/29-30 and Halloween morning dawned with a low of 32°, the coldest reading in October since 1988.  This was three weeks earlier than the average date of the first freezing or colder reading in Central Park.

 

Jack_frost

 

The month's mildest reading was 74° (on 10/7), which was the coolest warmest reading in October since 2009, which also had a mildest reading of 74° (October 2009 was the last time the month was chillier than average).  The last time the warmest reading was cooler than this was in 1987, when it was 72°.  (By contrast, last October's warmest reading was a sizzling 93°.)  There were just six days with highs in the 70s (the October average is nine), none of which occurred back-to-back.  This was just the third time this has happened in October in the past 100 years.  And this October was the only one of the three that was above average temperature-wise.

 

Chart - back to back 70s in Oct

Although the month was one degree milder than average, both the warmest and chilliest readings of October were six degrees cooler than what the average warmest and chilliest readings are in October.

 

Finally, there were just eight days with mean temperatures five degrees or more above average, and four days that were five degrees or more below average.  The lengthiest streak of days that were five degrees or more above average was five (10/20-24); this streak was nine degrees above average (high/low of 69°/58°).  There were no extended periods of significantly chillier than average temperatures, but the last two days of the month were twelve degrees below average (high/low of 47°/34°).

 

Geese on the pier

 

Here are previous recaps of October's weather:

2019

2018

2017

2016

 

 

 

 


September 2020 Weather Recap: Cool & Dry Conditions Sandwiched Between Mild & Wet

September 2020

 

September 2020 was a touch milder than average (+0.8 degree), with close to an average amount of rain (3.94").  The month's story can be told by three eight-day periods: Sept. 3-9 was four degrees above average, Sept. 23-30 was six degrees above average, and the middle of the month (Sept. 15-22) was six degrees chillier than average, and rain-free.  Nearly all of the month's nearly four inches of rain was produced by three storm systems: 0.71" on 9/3, 1.20" on 9/10 and 1.61" on 9/29-30. 

 

The month's near average rainfall belied a 16-day streak with no measurable rain (Sept. 11-26).  This was the longest dry streak since the fall of 2017.  These dry conditions were largely due to a strong high pressure system that anchored itself over the Northeast for about a week.  It prevented moisture from hurricane Sally and tropical storm Beta from moving into the area and brought chilly air into the region, delivering the City's earliest lows in the 40s in seven years (49° on 9/21, 48° on 9/22).

 

Just seven days had highs of 80° or warmer, joining ten other Septembers since 1970 with this few.  The warmest reading was 85°, occurring on 9/3 and again on 9/4 (a typical September's hottest reading is around 90°).  The month's average high of 75.5° was the coolest since 2009.  And although the month's average temperature was a touch above average, it was the coolest September since 2013.

 

Chart - septembers by decades

 

Finally, although highs in the 80s/90s and lows in the 70s occasionally occur in October, if 2020's final reading of 80°+ remains at 9/10, it will be one of the earliest dates on record for this occurrence.  Meanwhile, the 58 lows of 70°+ is the third most after 1906 (61) and 2005 (60). 

Here are previous September recaps:

2019

2018

2017

2016

2015

2014

 


August 2020 Weather Recap: A Continuation of Summer's Above Average Temperatures

Isaias august 2020

 

Like June and July, August was warmer than average, but not to the degree of the two preceding summer months.  It was 1.7 degrees above average and the 23rd hottest August on record.  This followed June, which was 16th hottest (2.3 degrees above average), and July, which was 7th hottest (+3.5 degrees). There were no scorching heat waves, but the number of days with lows in the 70s was above average.  Tropical storm Isaias, which struck on the 4th, was August's weather highlight followed by a thunderstorm on the 12th that was the month's biggest rain maker.  Overall, the month's 5.03" of rain was a touch above average.

 

There were four days in the 90s and six days with highs of 88° or 89°.  Hottest reading of the month was 92°. The two days with the warmest lows (78° on Aug 2 and 77° on Aug 11) failed to have highs of 90+.  There were no heat waves and none of the days in the 90s were back to back.

 

Tropical storm Isaias was largely a wind event, with well under an inch of rain measured.  A gust of close to 50 mph was clocked in Central Park while the area's major airports all had gusts around 70 mph.  By comparison, a severe evening thunderstorm eight days after the tropical storm produced 1.76", more than three times the amount from Isaias (0.55").

 

This was the seventh August in a row with no lows in the 50s (coolest reading was 62°).  There were 19 days with lows in the 70s, which was well above average (13).  Only six Augusts have had more; five others also had 19.  However, the number of days with lows of 75°+ was just slightly more than average, ranking 29th (and tied with six other years).  The fourth longest streak of days with lows of 70+, 20 days, ended on 8/7 (just two shy of the longest streak).

 

Finally, the summer of 2020 was the fourth hottest on record (tied with 1983).  However, it was tied for fourth warmest average low but 18th hottest average high.  Although rainfall was slightly above average it was enough to make 2020 the second wettest of the ten hottest Augusts (just 0.11" behind 1983).

 

Chart - 10 hottest summers

 Dog days of summer

 

Here are previous August recaps:

2019

2018

2017

2016

2015

 

 


July 2020 Is Seventh Hottest; Drought Eases Up

Seventh place

 

Following a June that was 2.3 degrees warmer than average, July 2020 was even more above average, +3.5 degrees, with an average high/low of 87.4°/72.6°.  The month's average temperature of 80.0° made it the seventh hottest July on record.  July records were set for mildest reading for coolest low temperature (67°) and the most lows in the 70s/80s (26).  Additionally, it joined eight other Julys with 14 or more highs of 90° or hotter.  Low temperatures were instrumental in placing the month so high in the rankings as it was third warmest in that category while the average high was ranked sixteenth.  Precipitation was also a significant story as the 6.58" that fell made this the wettest month of the year, so far, and the wettest of the 15 hottest Julys (July 2019 previously held that distinction).  Tropical storm Fay contributed a significant portion of the month's rainfall.

 

As mentioned above, July had 14 days with highs in the 90s, the most since 2010.  This included two five-day heat waves.  Despite the large number of hot days the heat wasn't overbearing as only one day had a high of 95° or hotter (96° on 7/6).  This was the fewest of any July among the 10 hottest.  However, there were nine days with lows of 75°+ (tied for fifth most of any July), including two in the 80s (the counterpart to high temperatures in the triple digits).  And of the six days with below average mean temperatures, just one of them had a low temperature that was cooler than average.

 

Highline during covid-19
.

After an exceedingly dry May and June, with both months reporting less than two inches of rain, July had 6.58", making it the wettest month so far this year (nearly double the combined rainfall of the preceding two months).  More than half of the rain was from tropical storm Fay on 7/10 (2.54") and a severe thunderstorm the evening of 7/22 that dumped 1.23" in an hour.  (Newark Airport, just 20 miles to the west, was much rainier, with 11.17" measured - its wettest July on record).

 

Chart - july 2020 top 10 julys

 

Finally, June and July 2020 were the seventh warmest June-July combination.  And the number of lows of 70°+ in June and July (37) tied June-July 2010 for the greatest number.  (37 is the  average number for an entire year.)

 

Chart - hottest june_july combos

 

Here are previous recaps of July from 2014 thru 2019:

July 2019

July 2018

July 2017

July 2016

July 2015

July 2014

  Tropical