December 2016 Summary – Warmer and Drier Than Average

Blue Hill Observatory
December 2016 Summary:

December continued the warmer, drier and sunnier than average weather that occurred in November and during much of 2016. The 24-hour mean temperature for the month of 32.1 deg F was 2.3 degrees warmer than the 120-year average for December and about a half degree warmer than the 1981-2010 30-year average. The highest temperature for the month was 56F on the 27th, and the low temperature of 1F occurred on the 16th. There were no daily temperature records during the month. December brought a total of 2.83 inches of precipitation, which was an inch and a half less than the long-term 120-year average and more than two inches less than the 30-year mean. The greatest amount in 24 hours in December was 0.87 inches on the 29th-30th. Snowfall totaled 7.8 inches, which was three and a half inches less than the long-term mean and five and a half inches less than the recent 30-year normal. The steady rainfall on the 29th quickly changed to a period of snow on the evening of the 29th that totaled 1.8 inches and was accompanied by thunder and lightning. This was the fifteenth thunderstorm day of 2016, well below the annual average of 22, and the first in December since 2011. The mean wind speed was 13.7 mph, and the prevailing direction was from th51west. The peak gust was 45 mph from the southwest on the 27th. December was sunnier than average with 52 percent of the possible bright sunshine, which was six percent more than the long-term mean for the month.

Mike Iacono
Chief Scientist
Blue Hill Observatory