December weather forecastJefferson, MA
December
Weather in December
December, the first month of the winter in Jefferson, is also a wintry month, with an average temperature fluctuating between 25.9°F (-3.4°C) and 36.5°F (2.5°C).Temperature
With December's arrival, Jefferson's weather changes as the average high-temperature falls from a frosty 46.8°F (8.2°C) in November to a wintry 36.5°F (2.5°C). In December, the recorded average low-temperature is a subzero cold 25.9°F (-3.4°C).Humidity
The average relative humidity in December in Jefferson is 79%.Rainfall
The month with the most rainfall is December, when the rain falls for 9.1 days and typically aggregates up to 2.76" (70mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Jefferson, in December, during 6.8 snowfall days, 3.5" (89mm) of snow is typically accumulated. In Jefferson, during the entire year, snow falls for 39.9 days and aggregates up to 24.45" (621mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 6min of daylight.On the first day of the month, sunrise is at 6:57 am and sunset at 4:15 pm. On the last day of December, sunrise is at 7:16 am and sunset at 4:25 pm EST.
Sunshine
The average sunshine in December in Jefferson is 4.6h.UV index
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for the average person.Note: In December, the maximum UV index of 2 transforms into these recommendations:
Babies, children, and individuals with sensitive skin should always have protection against extended sun exposure. Minimize direct exposure to the Sun during midday when its radiation is at its peak. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Jefferson, MA
- Average high temperature in December: 36.5°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (30.9°F).
- Average low temperature in December: 25.9°F
The month with the highest average low temperature is July (61.7°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in December
Jefferson, MA
- Average pressure in December: 30.04"Hg
The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Jefferson, MA
- Average wind speed in December: 8.6mph
The windiest month (with the highest average wind speed) is January (9.1mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).
Average humidity in December
Jefferson, MA
- Average humidity in December: 79%
The month with the highest relative humidity is February (81%).
The month with the lowest relative humidity is April (72%).
Average rainfall in December
Jefferson, MA
- Average rainfall in December: 2.76"
The wettest month (with the highest rainfall) is December (2.76").
The driest month (with the least rainfall) is September (1.69").
Average rainfall days in December
Jefferson, MA
- Average rainfall days in December: 9.1 days
The month with the highest number of rainy days is May (16.3 days).
The months with the least rainy days are January and February (6.8 days).
Average snowfall in December
Jefferson, MA
- Average snowfall in December: 3.5"
The month with the highest snowfall is February (6.06").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Jefferson, MA
- Average snowfall days in December: 6.8 days
The month with the highest number of snowfall days is February (9.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Jefferson, MA
- Average daylight in December: 9h and 6min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in December: 4h and 36min
The months with the most sunshine are July and August (Average sunshine: 10h and 0min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in December
Jefferson, MA
- Average sunshine days in December: 17.1 days
The month with the most sunshine days is November (17.8 days).
The month with the least sunshine days is June (12.8 days).
Average UV index in December
Jefferson, MA
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in December
Jefferson, MA
- Average cloud cover in December: 49
The month with the most cloud cover is March (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 36).
Average visibility in December
Jefferson, MA
- Average visibility in December: 6mi
The months with the highest visibility are April, November and December (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September and October (5mi).





