New York City Weather Archive

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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80-Degree Weather in April and October

On average, temperatures reach the 80s, or hotter, on 1.4 days in April and 1.1 in October (since 1970).  Interestingly, despite the higher likelihood in April, its average high temperature is a few degrees cooler than October's.  In the years between 1970 and 2019, April has had about 25% more 80/90-degree days than October (72 vs. 57 days).  However, this disparity didn't start until 2000.  Between 1970 and 1999 the two months were relatively close (35 days in the 80s in April vs. 31 in October), but since 2000 April has had 37 such days while October has lagged behind with 26.

 

The greatest number of 80-degree days to occur in April is five, which happened twice, in 1985 and 2002.  October 1990 had six 80-degree days and five in 1995 and 2007. The most years in a row without an 80-degree temperature being reported in April is three; the same holds true with October.  However, while the most consecutive years with 80-degree readings (or warmer) in October is four (2016-2019), April, has had a streak of thirteen years (2001-2013).

 

 

Since 1970 thirteen of April's days above 80 degrees have been in the 90s, but just one such day has occurred in October (it was in 2019 and was the first high of 90+ in October since 1941). 

 

 

Finally, there have been ten 80-degree days before April 1, but just one after November 1.  (March and November totals aren't included in this analysis.)

 

 

 

 

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Weather Analysis: Monthly Averages Can Deceive

April 2013 in New York was rather unique because it was just the third time since 1960 that a month had a mean temperature right at the monthly average, i.e., 0.0 degree difference.  The other two months in which this happened were August 1999 and August 1985.  However, what set April 2013 apart was the fact that its average high and average low were almost right at the average as well (-0.1/+0.1).  And while August 1999's high/low wasn't too far from average (-0.3/+0.3), August 1985's was significantly different (-1.3/+1.3).

 

April's near bulls-eye inspired me to examine all months that were relatively close to average, temperature-wise, to see how many had highs and lows both with departures from average of the same magnitude, and how many diverged significantly, but neutralized each other (like August 1985).  For my purposes I included all months that were either right at the average, or 0.1, 0.2 or 0.3 degree from average.  Since 1960 there have been 54 months that fit this qualifier (which translates to an occurrence of about once a year).

 

 

So, what were my findings?  Only five of the 54 months that reported a mean temperature close to average had highs and lows with departures from average that were nearly identical.  But perhaps the biggest finding was that March 2009 was actually closer to a 0.0 difference from average than April 2013, as its high temperature was 0.1 below average and its low was right at the average.  However, because of rounding, it ended up being 0.1 below average and not at 0.0 as April 2013 was. 

 

		Departure from Average		Spread Between
		High	Low	High/Low
September	1989	-0.2	-0.2	0.0
March	1980	+0.1	+0.1	0.0
MARCH	2009	-0.1	0.0	0.1
August	1990	-0.2	-0.1	0.1
June	1995	+0.2	+0.3	0.1

 

On the other hand, as the chart below shows, there are "average" months that have highs and lows that diverge wildly from their averages, but balanced each other to produce a monthly mean temperature that was "average".  The most extreme case was November 1977.  Although its mean temperature was 0.1 degree below average, the month's high was 2.5 degrees below average while the low was 2.3 above average.  Two months before that, September 1977, exhibited a similar wide divergence.

 

		Departure from Average			Spread Btwn
		Mean	High	Low	High/Low
November	1977	-0.1	-2.5	+2.3	4.8
September	1977	-0.2	-2.1	+1.8	3.9
September	1996	-0.2	-1.9	+1.6	3.5
June	1996	-0.2	-1.8	+1.4	3.2
April	1983	-0.1	-1.7	+1.4	3.1
October	1998	+0.1	-1.4	+1.5	2.9
March	2007	-0.3	+1.1	-1.6	2.7
August	1985	0.0	-1.3	+1.3	2.6
September	1982	-0.1	-1.3	+1.2	2.5
June	2006	-0.2	-1.3	+1.0	2.3
September	1960	-0.3	-1.4	+0.9	2.3

 

It's interesting to note that in all cases but one, the highs were below average while the lows were above average.  This greater propensity for low temperatures to increase is a classic sign of global warming, whereby a more persistent cloud cover, promoted by increased carbon dioxide levels, keeps heat from escaping at night.  

 

 

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New York Weather History: April (1970 - 2019)

Highlights:  The blizzard of April 6, 1982 dumped nearly 10 inches of snow; four inches of snow fell on April 4, 2003 and 5.5" on April 2, 2018; a nor'easter on April 13-14, 2007 flooded the City with more than eight inches of rain; three consecutive 90-degree days occurred in mid-April 2002, including one 96° reading; other 90-degree weather has occurred in 1990, 1991, 2009 and 2010. April 2014 ended with a five-inch rainstorm, one of NYC's biggest rainstorms on record.

 

April 1

April 2

April 3

April 4

April 5

April 6

April 7

April 8

April 9

April 10

April 11

April 12

April 13

April 14

April 15

April 16

April 17

April 18

April 19

April 20

April 21

April 22

April 23

April 24

April 25

April 26

April 27

April 28

April 29

April 30

 

 

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Looking Back at New York Weather: April 30

 

1925

Rainy and very cool, with a high/low of 45/42.  The high was a record for the coolest maximum temperature on this date.

1940

Today's high of 67°, just a few degrees above average, was the mildest reading of the month.  (The warmest high temperature in April is typically in the 78° to 82° range.)  In the years since 1900 this is the only April not to have any readings of 70° or warmer.

 

1942

Today's high of 91° degrees, a record for the date, followed a high of 72° yesterday and 53° the day before that.  The previous record for the date, 86°, was set just last year.  In both years the humidity was very low during the afternoon, around 25%.

1962

After three days of summer-like warmth (highs of 91-89-80), the afternoon was raw and showery with temperatures only in the upper-40s.

1963

Up until today just 0.39" of rain had fallen in April and it appeared it would become the driest on record.  However, an all-day rain brought 0.89" and the month ended up tied for third driest April.  Until 2014, today's rainfall was a record for the date, which was the second smallest amount for a daily record (Sept. 9's daily record is 0.86", which was established back in 1902).

1990

Today's high of 56° (ten degrees below average) was quite a drop from 73° yesterday and 90° two days ago.

2012

The final nine days of April all had chillier than average temperatures - the longest such streak since the end of March last year.  But despite these below average conditions, the month was the unprecedented thirteenth in a row with above average temperatures. 

2013

With a high/low of 68/51, today's mean temperature was two degrees above average, just enough to move the month's mean temperature from 0.1 degree below average to right at the average.  Thus, it joined August 1999 and August 1985 as the only months since 1980 to have a mean temperature on par with the monthly average.  April's high was 0.1 above average; the low was 0.1 below average.  However, what was far from average was the month's precipitation, which amounted to just 1.31".  This was 71% below the norm of 4.51", making it the fifth driest April on record (and the driest in 50 years).

2014

Until this year April 30 was one of three dates that had never seen an inch of rain.  That distinction ended today as nearly five inches flooded the area, with more than half of it falling after 6PM.  The 4.97" that fell was the ninth greatest daily rainfall on record.  Besides the rain it was also a very raw day with temperatures only in the 40s.

 

2019

Today was the eighteenth day this month with measurable precipitation, the most of any month since May 2012, and the most on record of any April (the most of any month is nineteen days, in Dec. 1972 and May 1973).  However, despite this high frequency of rainy days the amount of rain that fell in April, 4.55", was just an average amount.  (Seven days had 0.03" or less.)  By contrast, New York's ten rainiest Aprils averaged 12 days of precipitation (ranging from nine to fifteen).  

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Today in New York Weather History: April 27

 

1915

Two days after the temperature soared into the 90s, they did so again today.  But after reaching 92° shortly before 4:30 (one degree hotter than 4/25) a cold front moved through a few hours later and the temperature dropped to 54° by midnight (similar to what happened two days ago.) 

 

1962

In a span of 13 hours the temperature soared from 51° at 1AM to 91° by 2PM.

1990

Just like 1962, the day's temperature soared from 51° to 91°.  This was the earliest date for a year's first 90-degree reading since 1977 (when it occurred on 4/12).

1994

0.41" of rain fell during a twenty-minute thunderstorm later in the afternoon (4:27-4:47 PM).  After a cool start (low of 50°) it turned into a warm day as the high reached 82°.

 

2007

2.07" of rain, a record for the date, brought April's rainfall total to 13.05".  This was a morning rainfall with a little more than half of the amount falling between 3:00 and 5:00 AM.

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Looking Back at New York City Weather: April 26

 

1984

Today's high reached 73°, the first 70-degree reading of the year.  This was four weeks later than average and the latest since 1956 when it occurred on 4/28.  No year since has had a later date.

2009

Today's high reached 92°, a record for the date and twenty-seven degrees above average.  It came just three days after a chilly high of 57°.  This was the second day of a four-day springtime heat wave that saw high temperatures of 88-92-84-90.  (The typical high in late April is in the mid-60s.)  It would be nearly four months before it got this hot again. 

 

 

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Today in New York Weather History: April 25

 

1915

Today saw perhaps the greatest swings in temperature of any date in New York's history.  After first steadily climbing from 47° shortly after midnight to 91° at 3PM, the temperature then plunged to 52° by midnight.  This was the result of a strong warm front moving through for about ten hours (9AM-7PM) and then being displaced by a backdoor cold front.  There was no rain produced by the passage of either front.  Two days later the temperature would rebound into the low 90s only to drop again like a rock after nightfall.  These crazy swings came three weeks after 10.5" of snow buried the City.

 

1919

It was a cold day, with temperatures more like winter than the middle of spring.  The high/low was just 43/29, nineteen degrees below average.  And tomorrow's readings were very similar (44/31).  Both days also had winds that gusted to 25 mph, making it feel like it was in the 30s.

1960

After a seasonably cool low of 48° the temperature rose sharply, to 87°.  Meanwhile, although they were still milder than average, yesterday and tomorrow had highs of 70°.

1962

For the third year in a row a big jump in temperature occurred on this date.  This year the mercury jumped from 48° to 84°; in 1961 it rose from 49° to 82°; and in 1960 the high reached 87° after a low of 48°. 

1976

Five days after an unprecedented four-day heat wave ended (with highs of 91-96-92-89), today was the first of three days in a row with highs only in the 40s (49-46-49).  

2002

A steady rain, amounting to 0.55", fell during the afternoon - the first rain on this date in 12 years.  One week after a heat wave, with temperatures 30 degrees above average (comparable to hot temperatures experienced 1976's), today was chilly, with a high/low of 52/43.

 

2007

For the sixth year in a row rain fell on this date as mid-afternoon showers amounted to 0.14".

2009

What a spectacular start to my summer share at Fire Island as the afternoon high soared to 88° (in NYC) after a low of 52°.

 

2010

After just 0.61" of rain fell in the first twenty-four days of the month, 1.60" poured down today.  The rain came from two storm systems.  The first brought the bulk of the rain in the AM hours (1.13"), the second moved in after dark.

2018

It was a dreary, showery, fog-shrouded day.  The 0.95" that fell (much of it between 6-9AM and then just before midnight) pushed April's total precipitation past the five-inch mark, the third month in a row with five inches or more.  The last time this happened was Sept-Oct 2011, but that three-month period had more than twice as much precipitation (34.43" vs. 16.45").

 

 

 

 

 

 

 

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Today in New York Weather History: April 24

 

1930

This was the second cold day in a row, with temperatures that were more typical of the first week of March.  Today's high/low of 44/31 followed yesterday's 42/32.  Both morning lows were records (which still stand).  These were the coldest days of the month.

1998

The 0.03" of rain that fell today, following yesterday's 0.82", duplicated the rainfall of 4/19 (0.82") and 4/20 (0.03").

2001

After soaring to 87° in the early afternoon (the warmest reading of the month), a cold front moved through and by midnight the temperature had fallen to 52°.  The colder air was made even chiller by winds gusting between 30-40 mph.  This was the third day in a row with 80-degree temperatures, and today's high was the warmest in more than eight months (since Aug. 9).  It was also the warmest reading in April in ten years.

 

2011

With a high of 80° (sixteen degrees above average), this was the warmest Easter Sunday since 1976 (when the high was a sizzling 96!).  However, showers between 6-9PM put somewhat of a damper on the day.  The 0.50" of rain that fell was the most on Easter Sunday since 1996.   

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Today in New York Weather History: April 23

 

1952

This was the sixth day in a row with a high of 74° or warmer.  The average high during this streak was 78°, which was 15 degrees above average.

1977

This was the 18th day in a row with no measurable rain.  This followed a rainy four-day period (4/2-5) in which nearly three inches fell. 

1979

Today's high reached 81° under clear skies, the first 80-degree day of the year (a day later than the typical date for the first 80).  

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