December 2013 Climate Summary for northern and eastern Maine

December 2013 finished with well below normal temperatures and well above normal snowfall.

Temperatures averaged from 4 to 7 degrees below normal across northern and eastern Maine, with the coldest anomalies across far northern Maine.  Snowfall was well above normal, and in most spots was 200 percent or more of normal.

The average temperature at caribou of 12.9 degrees was 5.3 degrees below the 1981-2010 average temperature.  There were only 9 days with an average temperature that was above normal, and there were no days with a high temperature above freezing after the 6th. It was the coldest December since 1989. At Bangor, the average temperature of 18.8 degrees was 5.8 degrees below average.  It was also the coldest December since 1989.

As far as snowfall goes, Caribou ended up with 44.8 inches of snow making it the 4th snowiest December on record, but well shy of the all-time record of 59.9 inches in 1972.  Caribou had an amazing string of 13 consecutive days with measurable snowfall from the 15^th through the 27^th, which broke the all-time record number of consecutive days with measurable snowfall of 9 days set in February 1960 and later tied in January 1991. There were 23 days with measurable snowfall, which was the most ever in December, and tied with January 1967 for the most days in one month with measurable snowfall.

At Bangor, a total of 28.6 inches of snow was observed which made it the 7th snowiest December on record, but well shy of the all-time record of 50.2 inches in 1970.

The month began with a snow pack of 1 to 5 inches across most of northern Maine, with no snow along the immediate coast.  A series of storms brought significant snowfall from the 15th through the end of the month.  By the end of the month, the snow pack was mostly between 1 1/2 and 2 feet across northern and eastern Maine with less than 1 foot along the coast.

There were several major winter storms that affected the area.  The first was on December 15^th and 16^th that produced widespread totals in excess of a foot across northern and eastern Maine including the immediate coast.  The highest totals of near 1 1/2 feet were observed across eastern Aroostook County.  Another storm quickly followed on December 17^th into the 18^th and mainly impacted coastal Hancock and coastal Washington counties with 6 to 12 inches of snow.

The most significant event was a multi-day ice storm that affected Downeast Maine the week before Christmas.  The storm left tens of thousands without power after more than an inch of ice accreted on trees and power lines.  It took a few days before power was restored to the majority of residents, and over a week in the more rural areas.  The storm was followed by a storm on the 29th the dumped over a foot of snow in across interior Downeast in many of the same areas that were hard hit by the ice storm.  The month ended with bitter cold on the 30^th and 31^st with many spots across northern Maine not getting above zero.

Overall the wind was relatively light this past December with an average wind speed at Caribou of 6.7 mph.  There were only 2 days at Caribou with an average wind speed above 10 mph.  The peak wind speed for the month was only 31 mph on the 30th.  At Bangor, the average wind speed for the month was 6.3 mph, and there were only 3 days with an average wind speed over 10 mph. The peak wind speed for the month was 40 mph on the 15th.