Boston Weather in December
Boston, Massachusetts usually experiences its first truly wintery weather of the season in December. Winter's first snowstorms arrive and so do days when the temperature remains below freezing.
This page gives detailed information on the typical December weather for Boston.
You can jump directly to data and descriptions for:
The numbers here are historical averages based on climate data gathered at Boston's Logan International Airport, located on the waterfront next to Boston Harbor.
|41 °F||December average high||5 °C|
|28 °F||December average low||-2 °C|
In most years, Boston averages a daily maximum temperature for December that's between 37 and 45 degrees Fahrenheit (3 to 7 degrees Celsius). The minimum temperature usually falls between 24 and 32 °F (-4 to 0 °C).
The days at Boston cool rapidly during December. By the end of the month, the temperature has dropped over 9 °F (5 °C) below what it was at the start.
|17 days||40 °F max. or more (4 °C)|
|21 days||32 °F min. or less (0 °C)|
Boston averages 1 day in December when the thermometer reaches into the 60s °F (over 15 °C). A temperature above 70 °F (21 °C) in December has happened about once a decade. Typically on 5 days the mercury remains below freezing for the entire day.
December has one night on average when the thermometer dips to 10 °F (-12 °C) or below. But the weather does not normally get as cold as 0 °F (-18 °C).
|3.8 in||total precipitation||96 mm|
|12 days||of rain or snowfall|
Half the time, Boston receives 2 to 5 inches (54 to 135 mm) of precipitation in December. One in four years has drier weather, while another one in four is wetter.
|9.0 in||total snowfall||22.9 cm|
|5 days||with new snow|
December's snowfall varies a lot from year to year in Boston. Between 3 and 12 inches (9 to 29 cm) of fresh snow arrives in half the years. Less new snow lands in one out of four Decembers, while another twenty-five percent are snowier.
Boston typically has at least an inch (2.5 cm) of snow on the ground for 5 days this month. The snow normally accumulates to 5 inches (13 cm) or deeper on 2 days.
|9 days||clear skies|
The sun's rays reach the ground in Boston during 52 percent of daylight hours on average in December, for a total of 147 hours in the month. Typically on 9 days this month the sky is mainly clear, with at most 30 percent cloud cover.
Sunlight in December at Boston lasts for 9 hours and 8 minutes a day on average. The shortest days of the year, from around December 18th to 24th, last 9 hours and 5 minutes from sunrise to sunset.
|65 %||December average humidity|
The relative humidity in Boston during December usually peaks at 71 percent in the morning then drops to 59 percent by early afternoon.
|Local Time||1 am||4 am||7 am||10 am||1 pm||4 pm||7 pm||10 pm|
|13.2 mph||December wind speed average||21.2 kph|
December is a little windier than most other months in Boston.
|1 day||snowfall of 3 inches (8 cm) or more|
|0 days||with thunderstorms in December|
The first substantial snowfalls of winter for Boston usually arrive in December.
About once in five years, a December thunderstorm passes over Boston.
These weather data are long-term historical averages provided by the National Climatic Data Center of the United States. The temperature and precipitation numbers are 1981-2010 normals while the humidity and thunderstorm statistics are 1961-1990 normals.