Winter 2019-2020 Summary – Fifth Warmest on Record

Blue Hill Observatory
Winter 2019-2020 Summary:

The winter (December-February) season was generally very warm with a few cold periods, average precipitation and after the first few days, very little snow. The 24-hour mean temperature for the winter of 32.7 deg F was 3.4 degrees warmer than the 120-year winter average and 3.7 degrees warmer than the 1981-2010 30-year average. It was the fifth warmest winter on record and the warmest since 2016-2017. The average maximum temperature was 40.1 deg F, which was the tenth warmest on record, and the average minimum temperature of 25.6 deg F was the sixth warmest. The season included the two warmest consecutive days ever observed in January including a high of 68F on the 12th that was the warmest for the season and tied the monthly record for warmest January temperature that was previously set on January 26th, 1950. This high temperature also surpassed the daily record for January 12th of 60F set in 2018. After the first eight days of December, which were cold and snowy, periods of cold weather during winter were very brief. The coldest temperature for the entire season was 4F on February 15th. The liquid equivalent precipitation total for winter was 12.47 inches, which was slightly less than the 120-year average and nearly an inch less than the 1981-2010 mean. The only significant snowfall during winter was 13.1 inches over the first three days of December including 5.7 inches on December 1st, which surpassed the previous record for the date of 2.0 inches in 1902. February brought just 0.6 inches of snow, which tied for the second lowest on record for any February. The winter snowfall totaled just 24.7 inches, which was about 19 inches less than the long-term mean and 20 inches less than the 30-year normal. Following a recent trend, the local ponds froze and thawed several times during the winter. The mean wind speed for the winter months was only 12.8 mph, which was the lowest on record for any December-February period and nearly 4 mph less than the long-term average.  The peak gust during winter was 71 mph from the west-southwest on February 7th. Winter was much cloudier than average with 369.2 hours or 43 percent of the possible bright sunshine being observed, which was five percent less than the 120-year winter average of 48 percent.

BHO Warmest Winter (Dec-Feb) Mean Temperature, deg F (1886-2020):

1) 34.9 in 2015-2016
2) 34.8 in 2001-2002
3) 34.3 in 2011-2012
4) 32.9 in 2016-2017
5) 32.7 in 2019-2020
6) 32.6 in 1997-1998
7) 32.3 in 1936-1937
   32.3 in 1998-1999
9) 32.2 in 1932-1933
10) 32.1 in 1990-1991

BHO Warmest Winter (Dec-Feb) Average Maximum Temperature, deg F (1886-2020):

1) 43.3 in 2015-2016
2) 42.7 in 2011-2012
3) 42.5 in 2001-2002
4) 40.7 in 1889-1890
   40.7 in 1936-1937
   40.7 in 1990-1991
7) 40.5 in 2016-2017
8) 40.4 in 1932-1933
9) 40.3 in 1998-1999
10) 40.1 in 2019-2020

BHO Warmest Winter (Dec-Feb) Average Minimum Temperature, deg F (1886-2020):

1) 28.0 in 2001-2002
2) 27.2 in 2015-2016
3) 26.5 in 2011-2012
4) 26.2 in 1997-1998
5) 25.7 in 2016-2017
6) 25.6 in 2019-2020
7) 25.2 in 1948-1949
8) 25.1 in 1932-1933
9) 25.0 in 1936-1937

BHO Lowest Winter (Dec-Feb) Mean Wind Speed, mph (1886-2020):

1)12.8 in 2019-2020
2) 13.1 in 2013-2014
   13.1 in 2018-2019
4) 13.3 in 2011-2012
   13.3 in 2014-2015
   13.3 in 2017-2018
7) 13.5 in 2015-2016
8) 13.6 in 2007-2008

Mike Iacono
Chief Scientist
Blue Hill Observatory