Weather in December in Boston, Massachusetts

< December >
	Normal Max/ High Temperature	5°C (40°F)
	Average Temperature	1°C (34°F)
	Min/ Low Temperature	-3°C (27°F)
	Average Sea or Water Temp	4°C(39°F)
	Normal Precipitation	102mm (4in)
	Number of Wet Days (probability of rain on a day)	10 (32%)
	Average Sunlight per day	05h 19'
	Average Daylight per day	09h 07'
	Sunny (Cloudy) Daylight Hours	59% (41%)
	Sun altitude at solar noon on the 21st day.	24.2°

• The average sea tempeature is 4 °C (39.2 °F).
• The average temperature in Boston, Massachusetts in December is very cool at 0.9 °C (33.62 °F).
• Afternoons can be cool with average high temperatures reaching 4.7 °C (40.5 °F).
• Overnight temperatures are generally slightly cold with an average low of -2.9 °C (26.8 °F).
• The variation/ range of daily average temperatures in December is 7.6 °C (13.7 °F).
• Precipitation averages for December are high with 101.9mm (4 in) recorded across 10 days.
• In December the blue above Boston, Massachusetts is slightly fair having on average an unexceptional 5h 19' of beaming sunlight daily.
• The shortest day is 9h 04' long and the longest day is 9h 17' long with an average length of 9h 07'.
• There are approximately 3h 37' per day when the sun is occluded by cloud, haze, fog etc.
• It is sunny approximately 59.5% of daylight hours and cloudy 40.5% of daylight hours.

Weather Trend Graph for December in Boston, Massachusetts, Usa