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

 

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.

 

 

 

 

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.

 

Other annual recaps:

2019

2018

2017

2016

2015

2014

2013

 

 

 

 

Comments

[Joaquin]

Although 2020 will be best be remembered by the COVID-19 pandemic, two months with no live sports, as well as civil unrest, there were a lot of noteworthy headlines by the weather! An historic hurricane season (passing 2005), warmth and cold, and yeah...

[William]

Not only was 2020 New York's second warmest year, but 2020 was also the Earth's second warmest year as well.

https://twitter.com/LeeGoldbergABC7/status/1349817061309079553

[Ken K. in NJ]

Hi Rob. Interesting study on something I hadn't thought about. Thanks. Along the same lines, I noticed that we just went thru a stretch of 11 consecutive days with highs in the same 10 degree range, the 40's. I'm wondering if that is any sort of record, either for January or for any month in general. I would imagine such a streak would be more common in warmer months where there is not as much day-to-day variation.

[rob]

Hi Ken, there was a 12-day streak in 1919 with highs in the 40s from Jan. 14-25. There may have been other extended streaks like this in January, but this one popped up easily as it was mentioned in the weather highlights for 1/25.

[Henry]

Although 2012 and 2020 had similar temperature trends, such as a mild winter, identical temperatures until mid-April, similar dates for the first and last 90-degree readings, and a hot July, there are also some stark differences between the two warmest years on record.

April 2012 was dominated by sunny, warm weather in the first 21 days of the month. April 2012’s warmest reading was a summer-like 88 degrees on 4/16, twenty degrees warmer than April 2020’s warmest reading.

In May, the coolest readings in the two years greatly contrast each other. May 2012’s coolest reading was 49 degrees, which is perhaps one of the “warmest” coolest readings ever recorded for May. May 2012 also had fourteen days with warm lows in the 60s. However, May 2020, whose coolest reading of 34, was the first May since 1978 to have a reading in the 30s.

In the two warmest years on record, the greatest contrast appears in November. November 2012 is the coldest November of the 21st century so far (later tied by 2019). November 2020 is now the warmest November on record.

These are just a few interesting observations I have made comparing New York City’s two warmest years on record. I originally had a full list of every comparison and contrast, but that list was too long to type and I accidentally timed out. So this is just a condensed summary of my observations. To be honest, I was hoping that 2012 would retain its status as NYC’s warmest year on record because it had a warmer, more pleasant spring (2nd warmest spring behind 2010).

[William]

this was the fifth consecutive calendar year with no reading of 97° or warmer, the longest such streak in a very long time. from 1902 to 1916, only 1911 and 1912 had a reading this hot. this probably occurred cause there actually happened to be a(n) (unusual) plethora of days in the first decade of the twentieth century with a low in the upper 70s and a high in the upper 80s.