December 2013 Summary – Cloudy and Variable

Blue Hill Observatory
December 2013 Summary:

The month was much cloudier than average with very variable temperatures and low wind speeds.  The 24-hour mean temperature for the month of 30.7F was about one degree warmer than the 120-year average for December, but it was about one degree colder than the 1981-2010 30-year normal.  Daily temperatures were highly variable with 16 days having temperature departures of 8 degrees or more with seven of these being positive and nine being negative. Five days had high temperatures in the 50s or higher and eight days had highs in the 20s. The maximum temperature for the month of 63F on the 22nd was a new record for the date surpassing 62F in 1994, and the coldest temperature of 7F was recorded on the 17th.  The total precipitation for December of 5.27 inches was slightly above average for the month.  Snowfall for December was a couple of inches above average at 15.5 inches, with most of this, 15.0 inches, occurring in a little over a week from the 9th to the 17th. The greatest snowfall in 24 hours was 6.8 inches on the 14th-15th. The mean wind speed for December of 12.3 mph was a new record low for December surpassing 12.9 mph in 2001, and the prevailing direction was W. The peak wind gust for December was only 48 mph from the NE during the snowstorm on the 15th.  This was one of the lowest peak gusts recorded in December in the past 50 years, with the lowest being 44 mph in 2001. The month was very cloudy, and bright sunshine totaled only 34 percent, making this the ninth cloudiest December on record. A total of twelve days during the month had no sunshine at all.