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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

 

 


Snow Creates Excitement, But Rain Gets No Love

 Sled riding in central park_time out ny

Pity the rain.  It doesn't generate anywhere near the levels of excitement accorded snow.  (In a Brady Bunch analogy, rain is Jan, snow is Marcia.)  Perhaps it's because snow is a seasonal treat confined mostly to four months of the year (in New York), while rain has a year-round presence.  Snow is also limited by geography, so persons from warm climates get a thrill when they encounter snow.  Sure, kids may enjoy jumping in puddles, and it can be comforting hearing the pitter-patter of rain on the roof, but rain never enthralls us the way snow does.  It possesses a certain "je ne sais quoi" that rain simply doesn't have.

 

Marcia-marcia-marcia

Perhaps the enthusiasm for snow comes from childhood memories, e.g., sled riding, making snow angels, building forts, school closings, Christmas.  And although rain may generate feelings of gratitude from farmers, it doesn't inspire the fevered anticipation of a snowstorm.  No sporting events have been inspired by rain, nor does anyone think back wistfully about rain that fell on someone's wedding day; or a downpour that washed out a summertime barbecue; or a deluge that rained out a baseball game (football games, by contrast, are rarely cancelled because of snow). 

 

There's also something magical about how a snowfall muffles the din of the City, and how its shimmering silver-white color scheme can light up a winter night.  Rain, on the other hand, leaves behind a muddy residue and litters the sidewalks with broken umbrellas.  (And when I was growing up in suburbia, worms would appear on the streets after a rainfall.)

 

Snow transforms the cityscape as it piles on top of railings, mailboxes and cars, and beautifully etches tree branches.  (I've always been amazed that snow is able to accumulate on Manhattan's busy streets.)  With rain, everything basically looks as it did before the rain started, except that surfaces take on a sheen when wet (especially at night).   Another contrast is that snow depths can be easily gauged by sight, but not so much with rain.  While it's easy to tell the difference between a few inches of snow and a foot of it, can you tell the difference between a quarter-inch rainfall and one of one inch?  (OK, perhaps there are more puddles.)

 

Winter 2017 - snow blindness

I can attest to the draw of snow since my most popular posts, by far, are those that analyze snowfall, with audience-traffic many times greater than posts about rain.  (I've written 30 posts about various aspects of snow, double the number I've penned about rain.)

 

It should be noted that the love for snow doesn't extend to sleet.  And rain's attempts at a brand extension, i.e., freezing rain, gets even less love than rain.  Despite the accolades it receives, snow is by no means perfect.  Shoveling can bring on a heart-attack; flights are cancelled; plows push snow back onto recently shoveled sidewalks; eyeglasses get broken during snowball fights, and dogs whimper from the sting of rock salt on their paws.  But, like a favored child, these personality flaws are largely overlooked.  

 

The weather hobbyists among us pore over snowfall totals, fixating on every tenth of an inch of accumulation.  We become infuriated whenever a forecast doesn't deliver on its promise, and, oh, how we dread a changeover to sleet, or, God forbid, rain!  By comparison, there is very little grousing when a rainstorm "fizzles" out. 

 

Central Park's weather station is held in low regard by many because it seems to report lower snow totals than surrounding sites.  For some reason, it tends to have the least efficient water: snow ratio.  It may very well be a gross generalization (albeit based on years of observation), but it just seems that if Central Park and each of the area's three airports receive an inch of liquid precipitation, this amount will produce eight inches in the park, a foot at Newark, and and an amount somewhere in between at LaGuardia and JFK.  Who knows why?  (Detractors of Central Park's weather station suggest incompetence.)

 

One area in which rain and snow seem to get equal treatment is automobile advertising, where cars on rain-slicked streets seem to be featured just as often as those shown bounding through snow-covered country roads.

 

Car advertisement in rain

 Car ad in snow_audi

Finally, the snow experience in Manhattan is different from that of the suburbs.  The beauty of the snow lasts for just a day - two days max.  The sound of snowplows scraping the streets can be grating, and the transformation of snow into slush at street corners is dispiriting.  And be on the lookout for snow crashing down from the tops of buildings!  On the positive side, snow often results in suspension of alternate side of the street parking regulations, and those of us who are apartment dwellers aren't tasked with shoveling, so we can walk around taking selfies to our heart's content, or put on cross-country skies and pretend to be on a ski weekend.  And perhaps the best thing of all is that the hustle-bustle of the City is silenced for a brief time.

 

Snow selfie dec 2020

 

Snow vs rain

 

 

 


 

 

 

 

 

 


Months With 20" or More of Snow

20

 

During the winter of 2021, February became the 36th month (since 1869) to have 20 inches or more of snow fall in Central Park.  This was the seventeenth February to gain this distinction, by far the most of any month (January's had eight occurrences; December's had six; and March, five).  Thirty winters have had one of these snowy months, and three have had two (winters of 1978, 1996, and 2011).  19 of the months with 20"+ had more than 25" (including Feb. 2021).  And four had 30" or more.  The snowiest month of them all is February 2010, which reported 36.9".  Below are more observations about these snow-choked months: 

  • The first month with 20" or more snowfall was December 1872, when 27.0" was reported.  Despite February being the month most likely to have 20"+ snow, it didn't have its first overly snowy month until 1894, which was later than the first 20"+ occurrence for December, January or March.  (November and April have never had 20" or more; however, November 1898 came very close, with 19.0".  The most snow in April was in 1875, when 13.5" was measured.)
  • The most consecutive winters to have a month with 20"+ snow is just two, which has happened five times, most recently during the winters of 2010 and 2011.  The most consecutive winters without one of these snowy months is twelve, from 1936 thru 1947.  And there have been three ten-year gaps.

 

Chart - consecutive winters with 20 inches

  • The most days of measurable snow during a month with 20"+ is eleven, which occurred in March 1916 (25.5" fell) and February 1920 (25.3").  The fewest days of measurable snow during a 20"+ month is two, in February 2006, when one storm accounted for all of the month's 26.9" (at the time, New York's biggest snowfall on record).  And in January 2016 there were three days of snow, with 27.5" of the month's 27.9" falling on two of the days (which supplanted February 2006's snowfall as New York's biggest of all time).

 

Chart - most days of snow in month

 

Snow at radio city

 

  • Nine of the thirty-six excessively snowy months had no snowfalls of a foot or more; five had biggest snowfalls that were less than ten inches.   The smallest biggest snow was 7.0" in Dec. 1904, followed by March 1916, whose biggest accumulation was 7.6".
  • In a winter with a month of 20"+ snow, the least total snowfall for the entire winter was the winter of 1979, which had 29.4"; the 20.1" that fell during February of that winter comprised slightly more than two-thirds of the winter's total.  And in the winter of 1925,  29.6" of snow fell, of which January 1925 accounted for all but 2.2".
  • Two of New York's ten snowiest winters had no months with 20" or more: 1874-75 is ranked seventh,  and 1960-61 is the City's ninth snowiest winter.

 

Chart - snowiest winters with no 20-inch months
 

  • All but five of the thirty-six months were colder than average, including the coldest month on record, February 1934 (which had 27.9" of snow), the coldest March on record (1888, 22.3"), and fifth coldest December (1872, 27.0") and March (1916, 25.5").   The most above-average month to have more than twenty inches of snow is December 1948 (+3.9 degrees), followed by February 1983 (+3.0 degrees); January 2016 (+1.9 degrees);  February 2006 (+0.4 degrees); and February 1994 (+0.2 degrees).
  • Finally, "honorable mentions" go to December 2003, which had 19.8", and January 2014, which had 19.7".

 

Feb 1 snowstorm nbc nightly news

 

Here are a number of other posts I've written which discuss snowstorms in New York:

Comparing New York's Three Biggest Snowstorms

A History of Back-to-Back Snowstorms

New York's Snowiest 30-Day Periods

Remembering New York's "Snowmageddon" of Winter 2011

Survey of New York Snowstorms by Winter (1950-2021)

 


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

 

 

 


Analysis of Back-to-Back Days With the Same High & Low Temperatures

The same

 

In the years I've spent poring over New York's daily weather data, I'd notice pairs of days with the same high and low.  This analysis is the product of my curiosity about how common such pairings are.  On average, two occur each year (2.3 to be exact).  The most has been ten, which happened in 1931 and 2010.  There have been ten years with five or more pairs, including 2020.  Twelve years have had none.  (Of course, if temperatures were reported to one decimal place, these type of days would be even rarer than they already are.)  Here are some more interesting findings:

 

  • There have been three streaks that had three consecutive days with identical highs/lows - in 1988 (Aug. 3-5, all with a high/low of 89°/76°); 1984 (May 5-7, highs/lows of 69°/53°), and 1879 (May 8-10, 69°/49°).  And during the summer of 2013, after a high/low of 83°/67° on July 30-31, there was another day with the same high/low two days later, on Aug. 2.
  • There have been 23 pairs that missed by one degree of having a third consecutive day with the same high/low.  The most recent occurrence was in December 2010, when 12/7 had a high/low of 36°/30° after a high/low of 35°/30° on 12/5 and 12/6.  And each of the streaks of three-days (mentioned above) narrowly missed being four-day streaks:
    • Aug. 3-5, 1988's streak missed being a four-day streak when the high/low on Aug. 6  was 89°/75° instead of 89°/76°.
    • May 5-7, 1984's streak of 69°/53° was followed on May 8 by a high/low of 69°/55°.
    • The day before 1879's streak of May 8-10, with highs/lows of 69°/49°, the high/low was 70°/50°.
  • There have been three back-to-back pairs of days: July 28-31, 2010 (89°/74° on 7/28-29 and 85°/66° on 7/30-31); March 3-6, 1952 (pairs of 36°/32° and 42°/31°); and Aug. 17-20, 1906 (pairs of 85°/71° and 87°/77°).  And there has been one instance of three consecutive pairs of days: Dec. 16-21, 1901 (26°/20° on Dec. 16-17; 28°/20° on Dec. 18-19; and 26°/19° on Dec. 20-21).  (March 1952's and August 1906's streaks narrowly missed having three consecutive pairs.)
  • Of the 12 years with no pair of days, only one occurred after 1956 - 2000.  The other years: 1956, 1954, 1943, 1934, 1930 1924, 1916, 1903, 1889, 1881 and 1869.
  • There have been two instances of back-to-back years having the same pair of dates with the same high/low.  It first occurred on July 27-28, in 1897 and 1898.  (The pair of highs/lows in 1897 was 67°/64°, and 80°/74° in 1898.)  The second time was in 2020 and 2021 on May 29-30 (highs and lows of these pair were 81°/67° and 51°/47°, respectively).  And there have been five instances of pairs of the same dates being two years apart, most recently in 2018, when it and 2016 each had a pair of days on Dec 23-24.
  • July 27-28 has had the same high/low in six years, the most of any pair of dates: 2007, 1988, 1939, 1910, 1898, and 1897.
  • May 18-19, 1932 and May 18-19, 2005 had the same pairs of highs/lows (70°/53°).
  • There have been four pairs of 85°/70° highs/lows, which is the most frequent of any pair  (occurring on July 4-5, 2017; May 27-28, 2015; June 25-26 2014; and June 27-28, 1994).
  • July and August are the months most likely to have seen pairs of days with the same high/low (48 and 51 occurrences,respectively); February and October are the months least likely to report a pair of these days (with just 12 each). 
  • Hottest pair: 100°/79° on July 9-10, 1937; Coldest pair: 23°/14° on Jan. 28-29, 1986.

 Chart - back to back days_same high low

 

 


Review of 2020's Weather - New York's Second Warmest Year

Looking back

 

2020 was 2.4 degrees above average and became New York's second mildest year, behind 2012.  Only two months during the year, April and May, were chillier than average.  November became the mildest on record, July the seventh hottest, and February and March each became the eighth mildest.  January finished just outside the top 10, ranking eleventh, and June made it to sixteenth.  The summer was the fifth hottest (tied with 1983).  Despite 2020's warmer than average theme, there were some moments of chilliness worth noting:

 

  • April had no highs in the 70s or 80s for the first time in 80 years.
  • For the first time since 1978, May had readings in the 30s, and the low of 34° on the 8th was the coldest reading in May since 1891.
  • The year's last reading of 80° or warmer was on Sept. 10, which was the earliest of any year with 20 or more days with highs of 90°+.  A typical 90s/100s season lasts about three months (late May through late August), but in 2020 it was two months long (late June through late August).  However, the number of days in the 90s in 2020 was slightly more than average (20 days).
  • Later in September, the low of 49° on Sept. 21 was the the earliest for a low in the 40s since 1993.
  • Halloween had its first low of 32° or colder since 1988.

 

 Chart - 5 warmest years thru 2020

 

Chart - monthly temperature departure 2020

 

OTHER HIGHLIGHTS

  • The first half of the year was dry as the 16.15" measured was eight inches below average (the seventeenth driest first half on record).  The second half, however, had nearly twice as much precipitation, with 29.20" measured (three-and-a-half inches above average).  May and June both had less than two inches of rain, the first time since 1993 that these  months were this dry.  Overall, 2020 had 45.35" of precipitation, 4.59" below average.
  • Jan. 10 and 11 had record highs of 69° and 68°, respectively.  Meanwhile, chilly April's warmest reading was 68°, the first time since 1940 that April's mildest reading wasn't 70° or warmer.
  • The winter of 2020's last measurable snowfall was on Jan. 18, the earliest date on record for a last snowfall (breaking 2002's record by one day).  At the end of the year December's snowstorm produced more than twice as much as the previous winter.
  • Four tropical systems moved through the area.  The year's biggest rainmaker was from the first, tropical storm Fay, on July 10, which produced 2.54" of rain, most of it falling in a three-hour period during the afternoon.  While Fay brought the rain, tropical storm Isaias on Aug. 4 delivered ferocious winds, with 65-75 mph gusts common outside of Central Park (which had a peak gust of 48 mph).
  • July's coolest reading of 67° was the mildest coolest reading of any July.  Furthermore, July 2020 had the most lows in the 70s or warmer of any month (26).  This helped July become just the seventh to have an average temperature of 80° or above.
  • November had its first streak of six days with highs in the 70s (Nov. 6-11).  Later in the month, Thanksgiving Day's high of 65° tied for third warmest, and its low of 55° was mildest ever on this holiday.  The 0.79" of rain in the morning was the seventh greatest amount for Thanksgiving.
  • The 10.5" snowstorm of Dec. 16-17 was the biggest December snowfall in 10 years and the 13th during the month of 10 inches or more.  And at 1.7 degrees above average, December 2020 was the second mildest to have more than ten inches of snow.
  • An intense storm system on Christmas Day morning dumped the third greatest amount of precipitation on the holiday (0.92").  The day's high of 61° was the eighth reading in the 60s on the holiday.  The temperature dropped 32 degrees by midnight, which was the biggest daily drop in temperature all year.  2020 became just the second year (2015 is the other) to have highs in the 60s on Christmas Day (61°), Thanksgiving Day (65°) and Easter Sunday (63°).
  • Finally, the temperature profiles of 2020's first and last month were nearly identical.  However, December had more than twice the amount of precipitation than January and nearly five times as much snowfall.  Despite their similar temperatures January's was much more above average.

 Chart - jan v dec 2020

Other annual recaps:

2019

2018

2017

2016

2015

2014

2013

 

 

 

 


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

 

 

 


Dry Months in New York

Drier than normal

 

For the purposes of this analysis a dry month is one that had less than two inches of precipitation.  In the years since 1869, 18% of all months have been this dry, or about two months each year.  The most dry months in one year is six, which happened in 1910, 1946 and 1965.  The most consecutive months with less than two inches measured is four, which occurred in 1881 from July thru October.  Finally, there have been 15 years in which no month had less than two inches - most recently in 2018 (two of these 15 years were consecutive, in 2010 and 2011).

 

Graph - precip of less than 2 inches by month

 

CONSECUTIVE DRY MONTHS WITHIN A YEAR

The most consecutive months with less than two inches of precipitation is four, which happened in 1881 between July-October (1.25", 0.86", 0.97" and 1.60").  There have been nine other years that had three dry months in a row, the most recent being in 1993.  The smallest amount of rain during one of these streaks was 2.98" in 1910 (July-Sept.).

 

Chart - 3 months in a row with less than 2 inches

 

Two of the three years that have had six months with less than two inches of precipitation, 1910 and 1965, are among New York's ten driest years, but the third, 1946, is ranked 27th.

Five Octobers in a row from 1946-1950 had less than two inches of rain.  And there have been three other months that had this little precipitation in four consecutive years: January 1954-57; May 1902-05 and September 1884-87.  And seven of the nine Novembers between 1901-09 had two inches or less.

 

LESS THAN ONE INCH OF RAIN

Nearly one out of four dry months had less than one inch of rain, or about once every two years.  The greatest number of these very dry months in one year is three and it's happened twice, in 1881 and 1955.  The most years in a row to have the same month report less than one inch is two, which has happened three times: July 1954 (0.96") & 1955 (0.51"); Sept. 1884 (0.21") & 1885 (0.41"); and Oct. 2000 (0.68") & 2001 (0.66").

 

DRIEST MONTH OF EACH YEAR

On average, the driest month of a year has had 1.24" of precipitation (and most likely to happen in October).  About 40% of all years have had less than an inch of precipitation during their driest month.  June 1949 is the driest month of all time, with just 0.02" measured; the driest month in recent years is October 2013, which had just 0.36". The most consecutive years with a driest month reporting less than an inch is four, which was between 1999-2002.  

Thirteen years have had more than two inches as their driest month.  And two of them had more than three inches: 3.04" in 1975 and 3.03" in 2011. 

In both 1980 and 1981 the driest month had 0.58" of precipitation, and it was in consecutive months - Dec. 1980 and Jan. 1981.  And later in 1981, August had 0.59".  Two other years' second-driest month also had just 0.01" more than the driest month (1900 and 1975), while 1926's second driest month had 0.02" more.  And in 2000, 2001 and 2002 the driest months had 0.68", 066" and 0.71", respectively.

In the three consecutive years between 1903-1905, May was the driest month, and in the three consecutive years 1945-1947, October was the driest month.  Finally, in the four-year period 1967-1970 three of the years had January as their driest month (1967, 1968 and 1970).

 

Graph - driest month of year since 1869

 

Arid


Notable December Cold Snaps

The weather outside is frightful

Nearly 40% of Decembers since 1869, or 59, have experienced cold snaps/cold waves that lasted five days or longer (about half were seven+ days).  The most recent occurred in 2017.  In addition to the five-days+ qualifier, a cold snap needed to have an average high temperature of 32° or colder to be part of this analysis.  The longest of them lasted 15 days, in 1876; six have had sub-zero readings; six had twelve inches of of snow or more; and six had no snow whatsoever (not even a trace).  Finally, six Decembers had two periods of Arctic cold.

 

COLDEST

The coldest December cold wave occurred in 1917, when the six days between Dec. 17-22 had an average high/low of 17°/2°.  Most recently, the last six days of Dec. 2017 had an average high/low of 23°/15°, which tied for ninth coldest.

 

Chart - coldest december cold snaps

LENGTHIEST

Fifteen Decembers have had cold waves lasting ten or more days.  The lengthiest was 16 days in Dec. 1904 (average high of 32°/22°), followed by a 15-day stretch in 1876 (27°/17°).  The coldest of these lengthy cold waves was one of 10 days in 1872 (24°/10°).

 

Chart - lengthiest december cold waves

 

TWO IN ONE MONTH!

Six Decembers had two significant cold snaps.  The last time it happened was in 1955, with one of five days and the other lasting six days (they were three days apart).  The two in 1917 covered 15 days (eight days apart).

 

Chart - decembers with two cold snaps

 

COLD SNAPS MORE PREVALENT 100+ YEARS AGO

The greatest concentration of Decembers with cold waves was between 1876 and 1904, when 20 of the 29 Decembers had at least one cold snap.  The most consecutive Decembers to have a cold snap is four, which has happened four times: in 1901-1904, 1914-1917, 1932-35 and 1942-45; there have also been four three-year streaks, with the most recent being 1958-1960.  The most consecutive years without a cold snap is eight, and it's happened twice, in 1981-1988 and 2001-2008.  And there was a seven-year hiatus from 2010 to 2016.

 

SNOWIEST & LEAST SNOWY

Six cold snaps received more than 13 inches of snow.  The most was 22.5" in 1883 and 21.5" in 1872.  The most recent was in 2000 when 13.3" fell.  Five of the Decembers had snowstorms that dumped a foot or more, with the most being 18.0" on Dec. 26, 1872.  And although December 1942, with 6.0", isn't found on the "most snowy" list below, it's worth mentioning because it had measurable snow on six of the cold wave's ten days.

 

Chart - snowiest december cold snaps

 

At the other end of the snow spectrum, ten December cold snaps had no measurable snow.  Eight of them were five or six days in duration, but December 1870 and December 1989 lasted 11 and 10 days, respectively.

 Chart - december cold snaps with no snow

BELOW ZERO READINGS

Seven of the Decembers had at least one sub-zero low.  The most recent was in 1980 (on Christmas Day).  These cold waves accounted for all of the twelve sub-zero lows that have been reported in December.  And although December 1872 had no below-zero readings, it had the distinction of having six days in a row with lows in the single digits (ranging from 4° to 8°).  At the other end of the spectrum, the coldest temperatures of five December cold snaps was a relatively mild 18° or 19° (most recently in 1970).

 

Chart - subzero readings in december

 

 

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The Coldest Day of New York Winters

Frozen bryant park fountain

 

Since 1900 the average high/low on the coldest day of each winter has been 19°/6° (in the last third of the 18th century it was 14°/2°; in the 21st century it's risen to a relatively temperate 20°/9°).  The coldest day has occurred as early as Nov. 30 (winter of 1875-76) and as late as March 15 (winter of 1931-32).  Nearly half of the coldest days of New York's winters have occurred in the four-week period between Jan. 9 and Feb. 6.  For this analysis "coldest day" is based on daily mean temperature (average of high/low), not just the low temperature.

 

Chart - warming of coldest winter day

 

THE SPECTRUM OF THE BIG CHILL

The dates of the most frigid coldest winter day and the mildest coldest winter day are, in their respective years, one day apart.  The coldest of them all fell on Dec. 30, 1917, when the high/low was 2°/-13°.  At the other end of the spectrum, the mildest reading to have the distinction of being the coldest day of a winter was 31°/20° in the winter of 2001-02 on Dec. 31, 2001January 18 is the date to see the most coldest days of winter - six.  Three dates in February have been the coldest for five winters each: Feb. 2, Feb. 5 and Feb. 17.

 

Chart - coldest day jan 18
 

TWO MEASURES OF "COLDEST"

Although the coldest day is usually the same date as the coldest temperature, they have occasionally occurred on different dates (on average, in one out of four winters).  For instance, although the coldest reading of all time is -15°, the coldest day of all time, based on mean temperature, had a low of -13°.  Although this is two degrees "warmer" than the coldest reading, the day's high of 2° was six degrees colder than the high on Feb. 9, 1934, so it ended up with a mean of -5.5° compared to a -3.5° in 1934.  (The most recent instance was the winter of 2019-20 as its coldest day was on Dec. 19, with a high/low of 25°/16°, while the coldest reading was 14° on 2/15.)

 

SIMILAR DATES

A number of consecutive years, or a few years apart, have had their coldest day on practically the same date.  And in one interesting case the coldest day of winters one hundred years apart (1916 and 2016) occurred on the same date - Feb. 15.  And the coldest day of the winters of 1884 and 1984 were two days apart, on 12/23 and 12/25, respectively.

 

Chart - coldest day same date

Chart - coldest day same date - 2

Chart - coldest day same date 100 years apart 

FRIGID HOLIDAYS

The coldest day of some winters has fallen on a holiday.  The one exception is Christmas Eve day.

 

Chart - coldest winter day on holidays

 

"COLDEST COLDEST, MEET MILDEST COLDEST!"

Of course, the coldest winters have a lot of very cold days that that would easily qualify as the coldest dates of many of the winters with average or above average temperatures.

 

Chart - coldest coldest day of winter 
 Chart - mildest coldest day of winter

 

SOMETIMES IT SNOWS

Snow falls very infrequently on the coldest day of the winter - just six winters have had an inch or more of snow on this day.  However, a few were significant, with the stand out being the 12.5" accumulation on the coldest day of the winter of 1966-67 (Feb. 9, which had a high/low of 16°/7°).

 

Chart - snowy coldest days of winter

Finally, the coldest day of the winter of 1963-64 was preceded by a snowstorm that dumped 11.5" the day before, while three storms that followed the coldest day of winter by one day dumped more than ten inches.  The storm in February in 2003 dumped 16.3", but started on the coldest day of the winter, with 3.5" falling that evening.

 

Chart - snowy day before and after coldest day

   

 

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