Winter 2017-2018 Summary – Warmer and Cloudier than Average

Blue Hill Observatory
Winter 2017-2018 Summary:

The winter (December-February) season began cold and ended very warm with an intense cold period at the end of December into early January and a record warm February. The 24-hour mean temperature for the winter of 29.9 deg F was 2.6 degrees warmer than the 120-year winter average and 0.9 degrees warmer than the 1981-2010 30-year average. The highest temperature for the season was 70F on February 21st, which was the second warmest temperature ever measured in February and the earliest occurrence of 70F or higher in any year on record. The 14-day period from December 26th to January 8th was exceedingly cold featuring seven days that were more than 20 degrees colder than normal and six days with minimum temperatures of 0F or colder. The coldest temperature during winter was -8F on January 7th. The liquid equivalent precipitation total for winter was 13.20 inches, which was a half inch more than the 120-year average and slightly less than the 1981-2010 mean. Winter snowfall totaled 44.7 inches, which was just an inch more than the long-term mean and a half inch more than the 30-year normal. The largest single snowstorm brought 16.5 inches on January 4th with temperatures in the teens and 20s and with winds that gusted to 54 mph. Nearby Houghton’s Pond first froze on December 15th and thawed on February 22nd following two extremely warm days. The mean wind speed for the winter months was only 13.3 mph, which tied as the second slowest wind speed for any December-February period on record.  The peak gust during winter was 62 mph from the south, which occurred during warm weather and rainfall that began on December 5th. Winter was cloudier than average with 45 percent of the possible bright sunshine being observed, which was three percent less than the 120-year winter average of 48 percent.

BHO Warmest Winter Daily Maximum Temperature, deg F (1885-2018):

1) 74 on 7 Dec 1998
2) 72 on 29 Dec 1984
3) 71 on 24 Feb 2017
4) 70 on 1 Dec 2001
   70 on 6 Dec 2001
   70 on 21 Feb 2018
7) 68 on 26 Jan 1950
   68 on 24 Feb 1985
   68 on 25 Feb 2017
   68 on 20 Feb 2018

BHO Lowest Winter Mean Wind Speed, mph (1885-2018):

1) 13.1 in 2013-2014
2) 13.3 in 2011-2012
   13.3 in 2014-2015
   13.3 in 2017-2018
5) 13.5 in 2015-2016
6) 13.6 in 2007-2008
7) 13.7 in 2004-2005
   13.7 in 2012-2013
   13.7 in 2016-2017
10) 13.9 in 2001-2002

Photo Credit: Cape Cod Aerial

Mike Iacono
Chief Scientist
Blue Hill Observatory