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March 2021

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).  

28 - Early afternoon showers amounted to 0.27”, pushing September’s rainfall over ten inches (10.03”).  Not only was this the most rain to fall in September since 2004, it was the third month in a row with more than ten inches of rain  – the first time for such a streak (July had 11.09”, August had 10.32”).  However, this wasn’t Central Park’s rainiest three-month period, as the 31.44” that fell was  three inches less than the 34.43” that fell in Aug-Sept-Oct 2011 (18.95”, 9.39” and 6.09”, respectively).

 

OCTOBER

13 - Today was the fourth day in a row with a low of 61° (and the seventh day with this low since 10/3).  It was also the sixth day this month with a high/low stuck in the 60s, the most on record for any month.  (On average, October sees one of these days once every two years).  Persistent overcast skies were largely the reason for the temperature not rising much during the daylight hours. 

14 - This was the twelfth day in a row with a low in the 60s, a record streak for the month of October (breaking a tie with October 2018).  Interestingly, the low temperatures during this streak were all in the narrow 60°-62° range (but highs ranged between 65°-77°).  

15 – Today’s high of 79°, and low of 63° were the warmest of the month.  The low broke the 12-day streak in which the low temperatures were in the 60°-62 range°.  With 13 days with lows of 60+, this October tied October 1879 for the most lows this mild in October.

16 - Today was the 15th day in a row with an above-average mean temperatures (average of high/low), the longest such streak since the winter of 2019-20, when there was a streak of 18 days (Dec. 22 - Jan. 8).  This period was six degrees above average.  Meanwhile, a 13-day streak of lows of 60+ ended today, after a cold front swept through during the evening, dropping the temperature to 56 by midnight.  This cold front also produced showers that amounted to 0.25”, which was 0.01” less than what fell in the first half of the month (the least rain to fall in the first half of October since 2000).    

17 - Today was the first day since 10/1 to have a below-average mean temperature, as the high/low of 61°/51° was two degree below average.  (10/1's low was also 51°.) 

18 - At 49°, today's low was the season's first in the 40s - the second latest date on record (the latest was in 2005, on 10/20).  This occurrence was three weeks later than average. 

26 - After moving in late last night, a nor’easter dumped 3.30" of rain today, with 2.51” falling this morning, and 0.79” after dark (and it continued falling overnight).  This rain brought an end to what had been a dry October, with less than an inch of rain through yesterday.  Today’s rainfall came very close to the record for the date, 3.40” in 1943 (also produced by a nor’easter).  The storm’s total rainfall of 3.69” made it the third biggest rainstorm of the year, behind Henri's 8.19" in August, and Ida's 7.23" at the beginning of September.

29 - This was the third day this month with a low of 47°, which was the chilliest reading of the month - and the mildest reading for this designation in October (the previous record, 45°, was in 1946 and 1971).   October's coldest reading is typically in the upper 30s.  And today's high of 56 was the chilliest high temperature this month, just two degrees shy of the mildest chilliest high for October (in 1971).

30 - After a coastal storm brought 0.41” of rain last night, an additional 0.53” fell this morning (most of it before sunrise).  Today’s rain (an additional 0.04" fell tonight) brought total rainfall since 10/25 to 4.67”, making this the rainiest last week of October on record.  This more than made up for the 0.15” of rain that was measured in the first half of the month (the driest first half of October since 2000).

 

NOVEMBER

7 - Today was the 50th running of the NYC Marathon, and conditions were close to optimal for runners as temperatures were in the mid-40s to lower-50s range, winds were mostly calm, afternoon humidity was on the low side, and skies were fair (transitioning from clear in the morning to hazy during the afternoon).  High temperatures today and the previous three days: 53° (today)-52°-51°-50° (average high in the first week of November is in the upper-50s).     

10 - For the eighth consecutive day skies were mostly clear (last month, by contrast, featured a 10-day period between Oct. 4-10 that was characterized by overcast skies).  Today was also the tenth day in a row in which no measurable rain fell, making it the longest dry spell to begin November since a 15-day streak in Nov. 1978.  This 10-day rain-free period was in stark contrast to the last 10 days of October, which had 4.75” of rain.  

13 - A fast-moving cold front produced a severe thunderstorm this afternoon between 2-2:30, with hail (a rarity in Manhattan even in the summer, let alone in November), a brief downpour, and 40-50 mph wind gusts.  This line of storms was even more severe along the Jersey shore and on Long Island, where wind gusts between 60-79 mph were clocked.   Temperatures dropped from the low-60s to low-40s by evening.  The 0.33" of rain that was measured pushed the year's precipitation over 58", moving 2021 just outside of the top-10 wettest years.

 

 


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