New York City Weather Archive

Warming Trend: A Decade-by-Decade Analysis

Monthly temperatures for New York (Central Park) go back to 1869.  With this century-and-a-half treasure trove of data in front of me I calculated each decades' monthly temperatures.  As I immersed myself in the data a story emerged, which was that New York was noticeably cooler before 1930, and every month's coldest decade occurred in that period.  A second story was that the decade of the 2010s became the warmest decade for eight months (April thru October, and December).  Other findings:

 

• Comparing pre-1930 decades with 1930 onward shows that March has warmed the most (+3.5 degrees), followed by February (+3.2).  The least warming has occurred in September (+1.4 degrees) and June (+1.5).

• The biggest difference in temperature between a month's coldest and warmest decade has occurred with February and March.  In the 1880s March's mean temperature was 35.4° degrees while it was 42.9° in the 1980s, a warm up of 7.5 degrees.  In February the pre- and post- temperatures were 29.4° and 36.3°.

• While March in the years between 1930 and 1999 was 3.5 degrees warmer than the six decades before 1930, in the 21st century it has been 4.5 degrees warmer.  June, July and October were just 0.2 degrees warmer than their respective months in the 1930-1999 period.

• Until the 2010s the warmest decade for September and October was the 1940s.

• In the first two decades of the 20th century February was colder than January by a significant margin (29.9° vs 32.3°).

• Worldwide, the first decade of the 21st century has been the warmest on record, but New York's warmest decade was the 1990s. (However, the 2000s had NYC's mildest Aprils and Novembers.)  

 

COLDEST & WARMEST DECADES BY MONTH
	Coldest		Warmest
		Mean		Mean
	Decade	Temp	Decade	Temp
January	1880-89	28.7	1990-99	34.8
February	1900-09	29.4	1990-99	36.3
March	1880-89	35.4	1980-89	42.9
April	1870-79	48.1	2010-19	54.2
May	1870-79	60.1	2010-19	64.3
June	1910-19	69.0	2010-19	72.2
July	1880-89	74.6	2010-19	78.8
August	1880-89	72.0	2010-19	76.4
September	1870-79	65.4	2010-19	70.5
October	1890-99	55.5	2010-19	59.2
November	1870-79	42.0	2000-09	48.6
December	1870-79	32.8	2010-19	39.8
Source: NOAA Local Climatological Data

 

TEMPERATURE TRENDS OVER THREE PERIODS
	Mean Temperature			Degrees Diff
	Before			2000-2019 vs
	1930	1930-1999	2000-2019	Before 1930
January	31.0	32.6	33.0	2.0
February	30.9	33.9	35.6	4.7
March	38.3	41.5	42.7	4.4
April	49.5	52.1	54.0	4.5
May	60.7	62.6	63.2	2.5
June	70.1	71.6	71.8	1.7
July	75.2	76.9	77.4	2.2
August	73.3	75.3	76.1	2.8
September	67.0	68.3	69.7	2.7
October	56.0	57.8	58.2	2.2
November	44.0	47.3	47.7	3.7
December	34.4	36.6	38.8	4.2
FULL YEAR	52.6	54.8	55.7	3.1

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When March is Colder Than December

Typically the month of December is five degrees colder than March, but about every five years (based on records since 1960) March is colder.  2014 was one of these years as March, the coldest in 30 years, was three degrees colder than December.  Of the 34 years (since 1869) in which March was colder than December, the most extreme was in 2015 when it was 12.7 degrees colder (that December was the mildest on record).  Here are some other tidbits ...

 

• Of the years in which March has been colder than December, both months had below average temperatures in five of them.  The last time this happened was in 1916.  And in 1982 and 2006, despite March being colder than December, both months were milder than average.

• The most consecutive years in which December was colder than March is fourteen, from 1942 thru 1955.  However, there have never been more than two consecutive years in which March was colder than December. Finally, in the last two decades of the nineteenth century March was colder than December in half of the years. 

• Interestingly, one of the coldest March's on record, in 1960, wasn't colder than that year's December, which was also much below average.

 

LAST 10 YEARS WHEN MARCH
WAS COLDER THAN DECEMBER
	Mean Temp		Difference
	March	Dec.	March v Dec.
Average*	42.5	37.5	5.0
2015	38.1	50.8	-12.7
2014	37.7	40.5	-2.8
2011	42.3	43.3	-1.0
2006	43.1	43.6	-0.5
2001	39.6	44.1	-4.5
1996	38.9	41.3	-2.4
1994	40.7	42.2	-1.5
1984	36.7	43.8	-7.1
1982	42.0	42.8	-0.8
1971	40.1	40.8	-0.7
*1980-2010
GREATEST TEMP DIFFERENCE
(MARCH V DECEMBER)
	Mean Temp		Difference
	March	Dec.	March v Dec.
2015	38.1	50.8	-12.7
1984	36.7	43.8	-7.1
1891	35.8	42.3	-6.5
1923	36.8	42.0	-5.2
1885	30.6	35.7	-5.1
1911	34.7	39.4	-4.7
1888	30.0	34.7	-4.7
2001	39.6	44.1	-4.5

Weather Analysis: The First 60-Degree+ Reading of the Year

There are a number of ways to gauge how cold a winter has been: mean temperature; the number of days with sub-freezing highs or single-digit lows; streaks of days with below average temperatures; or a dearth of mild readings.  For instance, after the brutal winter of 2015 New York didn't experience its first 60-degree day until March 26.  That's more than seven weeks later than the average date for this occurrence (Feb. 3) - and the latest date since 1982.  Here are more interesting tidbits about the first reading of 60+:

 

• In the 19th century (1869-1899) the average date of the first 60+ reading in Central Park was March 8, and then between 1900-1970 the average date moved up to Feb. 23.  Since 1970 the average date has been three weeks earlier.

• Between 1900-1970 the first 60+ day occurred on March 1 or later in half of the years, but since 1971 it has occurred after March 1 just 20% of the time.

• Since 1900 the first 60-degree day has occurred on New Year's Day five times: 1919, 1966, 1973, 1979 and 2005.  (In 1966 the year's first 60+ reading followed 1965's last 60+ reading on New Year's Eve.)

• Looking at all years the latest date for the first 60+ reading was April 15, in 1877.  And nine other years had their first reading in the 60s between April 5 and April 13 (see chart below); the most recent year to have a date that late in 1970 (April 8). 

• Once every 10 years the first 60+ reading has occurred in the first three days of January, while once every 23 years the first 60 occurred on April 1 or later.

• In 2007 not only was the first 60-degree reading of the year very early (Jan. 5), the mercury on that day soared to 72°. 

• In 1997 and 1998 the first 60+ temperature occurred on the same date, a very early Jan. 3.  And 1906 and 1907 had their first 60s on Jan. 4 while 2017's and 2018's  was on Jan. 12 (in 2020 it fell on Jan. 11).  At the other end of the spectrum, 1962 and 1963 both shared March 25 as the date of their first 60.

• For four years in a row, 2005-2008, the first 60-degree reading occurred in the first nine days of the year.

• In 1943 the year's first 60-degree temperature, 63°, came just five days after the morning low was 8° below zero.

• The coldest temperature to occur on the same day as the first reading of 60+ was in the winter of 1957 when an Arctic front knocked the temperature down to 20° after the mercury reached 60° earlier in the day (on Jan. 23).

• The biggest jump in temperature from the day before the first 60+ reading was 25 degrees, in 1954, when the high jumped from 44° to 69° the next day.  The biggest increase in temperature the day following the first 60+ was 21 degrees, and it happened in 1917, when the high reading the day after rose to 83°.  Lastly, the biggest drop in temperature after the first 60+ was 33 degrees and it happened in three years: 1957 (from 60° to 27°); in 1939 (62° to 29°); and in 1913 (63° to 30°).

• The date of the first 60+ reading in five years was also the date of the first 70+ reading: in 1987 (March 7); 1969 (March 18); 1964 (March 5); 1963 (March 25) and 1893 (April 1).  Nine other years had their first 70+ reading the day after the first 60+, the last time being in 2007.

 

January/February 2014 Ranks Second Among New York's Snowiest Consecutive Months

The snow that piled up in New York during the winter of 2014 made it one of the ten snowiest on record (going back to 1869).  The bulk of the 57 inches fell in January (19.7") and February (28.8").  Their combined total of 48.5" is the second greatest amount of snow to fall in back-to-back months.  Only the winter of 2011 had a combo with more as December picked up 20.1" and January saw 36.0". 

 

Three of the winters found on the chart below had 20" or more of snow for both of the months: Jan/Feb 1978, Jan/Feb 1996 and Dec 2010/Jan 2011.  And three winters make two appearances: 1996, 2010 and 2011.  (If March 2014 sees nine inches or more it will also have two slots on the list.)

 

NEW YORK'S SNOWIEST BACK-TO-BACK MONTHS
(Since 1869)
Months	1st Month	2nd Month	Combined
Dec 2010/Jan 2011	20.1"	36.0"	56.1"
Jan/Feb 2014	19.7"	28.8"	48.5"
Jan/Feb 1996	26.1"	21.2"	47.3"
Dec 1947/Jan 1948	29.6"	15.3"	44.9"
Jan/Feb 1978	20.3"	23.0"	43.3"
Jan/Feb 1923	24.5"	18.8"	43.3"
Feb/Mar 1967	23.6"	17.4"	41.0"
Feb/Mar 2011	36.0"	4.8"	40.8"
Dec 1904/Jan 1905	21.6"	18.4"	40.0"
Feb/Mar 1896	9.5"	30.5"	40.0"
Jan/Feb 2010	2.1"	36.9"	39.0"
Feb/Mar 1914	17.4"	21.5"	38.9"
Jan/Feb 1994	12.0"	26.4"	38.4"
Dec/Jan 1996	11.5"	26.1"	37.6"
Dec/Jan 1893	27.0"	10.6"	37.6"
Dec 2003/Jan 2004	19.8"	17.3"	37.1"
(Analysis of data from www.NWS.NOAA.gov)

Mild One Day, Snow the Next - A History of Dramatic Change

This post was inspired by an eight-inch snowfall on Feb. 2, 2014 that occurred the day after the high reached 56°.  However, there was an even more drastic one-day change during the winter of 2017 when 9.4" of snow fell on Feb. 9, the day after the high was 62°.  This was the most drastic one-day change in weather conditions since March 16, 2007 when 5.5" of sleet and snow fell the day after a springlike high of 67° was reached. 

 

Since 1970 there have been twenty-eight instances of an inch or more of snow falling the day after a high of 50° or warmer; however, on only seven of those occasions was the accumulation four inches or more.  In addition to the three occasions mentioned at the beginning of this post, here are the four other dates it has occurred:

 

• March 29, 1970 - On Easter Sunday four inches of snow fell the day after a high of 54°.

• Feb. 2, 2009 - 4.3" of snow fell one day after a high of 53° was reported.

• Feb. 21, 2001 - A snowfall of 5.8" occurred the day after a high of 52°.

• Feb. 17, 2018 - A nighttime snowfall of 4.4" came at the end of a week that had three days with highs of 62° and a high of 58° on 2/16.

 

The following two snowstorms occurred the day after the high temperature was above average, but below 50°; however, they warrant mention because of the large amount of snow that fell:

 

• Jan 21, 2014 - 11.0" fell the day after a high of 46° degrees was reached.

• April 6, 1982 - 9.6" fell the day after the temperature topped out at 48°.   

 

Finally, a shout-out to the 1.2" of snow that fell on April 9, 2000 because it came the day after a high of 71°.

 

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New York Weather History: March

March Highlights: The Superstorm of 1993 (aka "Storm of the Century") dumped 10 inches of snow on March 13; three years earlier on the same date the high was 85°, the City's earliest 80-degree reading on record; a five-day heat wave at the end of March 1986 saw each day with highs in the mid-80s; the nor'easter of March 13, 2010 delivered NYC's greatest one-day rainfall ever for the month of March; in addition to this storm, other famous March nor'easters struck in 1980, 1984, 1997 and 2001 and 2010 (on March 30); March 2012 was the second mildest on record; March 2014 was the coldest in 30 years, but just 0.1" of snow fell; March 2015 was the snowiest since 1956. 

 

March 1

March 2

March 3

March 4

March 5

March 6

March 7

March 8

March 9

March 10

March 11

March 12

March 13

March 14

March 15

March 16

March 17

March 18

March 19

March 20

March 21

March 22

March 23

March 24

March 25

March 26

March 27

March 28

March 29

March 30

March 31

 

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Today in New York Weather History: March 31

 

In the years since 1980 (thru 2019) the average date for the last temperature of freezing or colder in Central Park is March 31.  It has occurred as early as March 1 (in 2020) and as late as April 17 (in 1980).

1937

The low today and the previous three days: 31° (today)-30°-29°-28° - all well below average (37°).

1964

The coldest reading of the month occurred this morning, 22°, and this temperature held steady for four hours.  Normal low for the date is in the upper 30s.   Today's high/low of 38°/22° was half of what it was six days earlier (75°/46°).

1987

March ended as it began, with a big rainmaker (2.36" fell on 3/1).  Beginning last night, rain continued thru early afternoon today, amounting to 2.00".  But in the days between these two storms just 0.57" of rain fell.

 

1989

Today's high of 44° (11 below average) came just three days after a high of 82°.

1997

A nor'easter with 30-45 mph wind gusts dumped 2.32" of rain in New York and record amounts of snow in New England on 4/1 (25" in Boston, 18" in Providence).  A few days earlier New York had been warned of the potential for significant snow accumulation as well, but too much mild air moved in for this to happen.   

1998

Today's high temperature hit 86°, tying March 29, 1945 for the warmest reading ever recorded in March.  This was the last day of a five-day spring "heat wave".  During this warm spell the average high/low was 82°/61°, twenty-six degrees above average.  The next 80-degree day wouldn't be for another six-and-a-half weeks - and it was the last time (thru 2020 that a temperature in the 80s was reported in the month of March.  Today also happened to be the home opener for the New York Mets (which they won in 11 innings over Philadelphia).

 

 

2003

Five years later the Mets weren't as fortunate playing their home opener on March 31.  Although the game was played under clear skies, the temperature hovered around 40° and a biting wind created a "feels like" temperature of 30°.  No surprise, this was the coldest Opening Day in the 1970-2015 period.  To make matters even worse, the Mets were pounded by the Cubs by a score of 15-2.

2011

This was the earliest date for a Yankees home opener (until 2019) and it was played in raw and damp conditions.  The high was only 43°, twelve degrees colder than average.  After morning showers, no rain fell during the game but showers resumed in the evening.

 

2012

Because today was cold (high/low of 43°/38°) and rainy, two March records were NOT set.  The month's mean temperature ended up 0.2 degree cooler than the mildest March on record (in 1945), while the morning's rainfall of 0.26" brought the month's total precipitation to 0.96", preserving March 2006's distinction as the driest March on record (0.80").  Still, this was the twelfth month in a row with above average temperatures, matching a 12-month streak in 1998-99.  Furthermore, this was the driest Jan-Feb-March since 1985.       

2016

The fourth mildest March on record came to a fitting end as the temperature this afternoon rose into the low 70s.  This was the fifth day this month in the 70s (and seven days had highs in the 60s).  Besides being mild it was also the sixth driest March, with just 1.17" measured - the driest month in two-and-a-half years - since just 0.39" was measured in October 2013.

2017

It was a topsy-turvy March, which came in like a lamb (70° on 3/1) and went out like a lion as today featured an all-day rain (1.51", which came down especially hard after 6 PM) and temperatures that were well below average (high/low of 43°/37°). 

 

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Today in New York Weather History: March 30

 

1942

The morning low of 33° was the coldest reading of the month (it also occurred on three other days), making this the only March on record to have no reading of 32° or colder.

1979

Today's high of 76°, twenty degrees above average, was the first 70-degree reading of the year.

1987

The mean temperature over the past eight days was twelve degrees above average, with an average high/low of 66°/47°.  Today was the coolest of these days with a high of 61°, six degrees above average.

1989

It was a gray, rainy, raw and windy day, with 0.76" of rain measured.  Afternoon temperatures fell into the mid-40s one day after the high was 76°.

1991

0.2" of snow fell today, two days after a high of 77°.  This was the only measurable snow to fall in March, and the final snowfall of the winter.  24.9" in total fell during the winter, the most since 25.4" was measured in the winter of 1984.  Despite today's snow, the temperature remained above 32°.

2001

It was a raw and nasty morning as wind and rain from a nor'easter lashed the area.  Moving in last night, 2.16" of rain fell today, a record for the date.  Central Park reported a wind gust of 49 mph.  It was also cold, with a high/low of only 43°/37°.

 

2007

Today had one of the lowest humidity levels on record as it fell to a Sahara-like 6% at 4 PM (typical humidity level at this time of day is around 47%).  Although the temperature rose into the upper 60s (13 degrees above average) the dry air made the air feel chillier, especially when the sun went down.

 

 

2010

The second strong nor'easter in little more than two weeks buffeted the area.  Like the previous one, this storm produced more than four inches of rain.  Beginning late on 3/28 (when 0.34" fell), it continued through this afternoon.  After 1.58" of rain yesterday, an additional 2.45" fell today (a record for the date, breaking the previous record from the nor'easter of 2001).  With today's rainfall the month's total precipitation reached 10.68", making it the wettest March on record.   

2013

It was a very pretty day, which was the Saturday before Easter, as the temperature topped out at 59° degrees under sunny skies.  This was the mildest reading of the month, making this the first March since 2001 to have its mildest temperature cooler than 60°.    

 

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Today in New York Weather History: March 29

 

1919

Today's high was just 31°, twenty-two degrees below average and the coldest high temperature since 1/12.  This came the day after the winter's biggest snowfall of 1.4".

1921

Between 4 PM yesterday and 6 AM this morning, a span of just fourteen hours, the temperature dropped by 56 degrees, from 81° to 26° - the steepest temperature drop on record.

 

1923

This morning's low of 10° (a record that still stands) came six days after a high of 76° (also a record, tied in 2012).

1970

Today was Easter Sunday, and rain that began before sunrise changed to sleet and snow after 10 AM.  When it ended late in the afternoon, four inches had piled up.  This was a record amount for Easter and the only snow that fell this month.  (At the time I was a teenager living in Pittsburgh which also had four inches of snow, but it arrived shortly before sunrise.  Although we headed out for Easter Mass we turned around and came home because roads were treacherous.)

 

 

1977

Today's temperature shot from 46° degrees to 81°.

1984

39 consecutive hours of precipitation, which began yesterday morning at 9:00, ended at midnight, totaling 2.60" (2.04" of it fell today).  There was only a two-degree difference between today's high/low (36°/34°).  3.3" of snow fell during the storm, but it was washed away by regular changeovers to rain. 

1985

Today was the third day in a row with much above average temperatures.  Although the sun was filtered through a light overcast, the temperature soared to 82° today, twenty-eight degrees warmer than normal.  Not only was it warm but also uncomfortably humid.  However, today's summer-like warmth was four degrees lower than the record for the date set in 1945 (the warmest reading ever reported in March, later equaled on March 31, 1998).  The average high over the past three days was 78°, a reading more typical of the second week of June.

 

1996

Beginning late last night and continuing through this morning, 4.1" of snow fell, the seventh snowfall of four inches or more this winter.  It brought March's snow total to 13.2", making it the snowiest March since 1967.  Besides being snowy it was also a cold month, the coldest March since 1984.  Today's high/low of 41°/31° was the ninth day this month that was ten degrees or more colder than average. 

 

1998

For the third day in a row the high temperature was in the 80s (81° today) - and there were two more days of this June-like warmth to follow.

2013

Today's mean temperature was one degree above average (high/low of 55°/40°), the first above-average day since March 13.  This 15-day streak of below average days was nearly six degrees colder than average and was the longest string of below-average temperatures since a 15-day streak in July 2009.    

2015

Although it was a bright and sunshiny day, the mean temperature was eleven degrees below average (high/low was 46°/25°).  This was the 28th day this year with a mean temperature ten degrees or more below average - the most since 1916 when there were also 28 days in the first three months.  This came one year after there were 27 days between January and March.  (The typical number is eleven.)

 

 

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Today in New York Weather History: March 28

 

1919

1.4" of snow fell in the afternoon, the biggest snowfall of the winter (coming two weeks after 1.3" fell).  This was the last snowfall of the winter, which had just 3.8" of snow in total - the least snow until the winter of 1973 when just 2.8" fell (and also passed by the winter of 2002).  Temperatures during the afternoon were only in the mid-20s, half of what the usual afternoon temperature is at the end of March.  

1921

After the temperature jumped from 49° to 82° between 5 AM and 2 PM, New York experienced its greatest one-hour drop in temperature when it plummeted 29 degrees between 4:00 and 5:00, from 81° to 52°.  The strong cold front that ushered in this cold air was accompanied by winds that gusted between 35 and 45 mph.  By midnight the temperature was down to 34° (and would fall to 26° by 6AM).  This 48-degree plunge is the greatest daily temperature drop on record.

 

1960

This was the first day during a very cold month (colder than January or February) to have an above average mean temperature.  And at 71°, this was the first day this year to reach the 70s.

1984

A developing nor'easter brought a mix of snow and rain during the afternoon that continued through tomorrow.  1.5" of snow fell today, but forecasts had predicted substantially more.  The temperature in the City was a bit too mild to support a snowstorm (high/low was 43°/34°).

 

1985

The afternoon temperature topped out at 78°, twenty-four degrees warmer than average and more typical for the second week of June (and four degrees warmer than yesterday).  However, this was not a record as there was an even more extraordinary warm spell in 1945. 

1991

After a seasonable high of 53° yesterday, today's high soared to 77°.

2005

After visiting my mother for Easter, today's flight back to New York from Pittsburgh took eight hours because of strong thunderstorms in the New York area.  2.98" rain fell, a record for the date.  This was the biggest rain producer in six months since tropical storm Jeanne dumped 4.66" at the end of September. 

 

2012

Today's high/low of 67°/44° was the sixteenth day this month with a daily mean temperature ten degrees or more above average - the most of any month since 1970 (until December 2015, which would have eighteen such days).  So far this year more one-third of the days were ten degrees or more above average. 

2013

Although the day's mean temperature was just two degrees below average, it marked the fifteenth day in a row with below average temperatures.  During this time temperatures were nearly six degrees below average.  There hadn't been a longer below-average streak since April 2007, when there was one of sixteen days.

2016

Although it was just 0.38", the rain that fell during the morning hours after sunrise (as a cold front approached) made this the rainiest day of the month.  (Between Feb. 25 and yesterday, a span of 32 days, less than an inch of rain fell.)  Then late in the afternoon very high winds began buffeting the area with gusts between 40-60 mph that continued overnight.

2018

Today, with a high/low of 52°/38° (one degree below average) was the 22nd day in a row with a below average mean temperature, the fifth longest streak of this kind in the years since 1953 (the year the NWS began reporting departure from average on a daily basis).  Temperatures during this streak, however, were just 4.5 degrees below average, which is the least below average of any streak of 15 days or longer.

 

2019

Temperatures were seasonable for the Yankees' earliest home opener, but sitting outdoors in readings no higher than the low-50s is was what you might expect at a football game.  Skies were sunny, but then turned lightly overcast after the game against Baltimore ended (which the Yankees won 7-2).  

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