December weather forecast
Jefferson, MA

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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.
Updated: Jun 22, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in December?

In Jefferson, 36.5°F (2.5°C) is the average high-temperature and 25.9°F (-3.4°C) is the average low-temperature during December. In July, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which combines relative humidity and air temperature, is estimated at 86°F (30°C).

What is the average humidity in December?

The average relative humidity in December is 79%.

What is the wettest month?

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.

How many days does it rain in December?

In Jefferson, in December, during 9.1 rainfall days, 2.76" (70mm) of precipitation is typically accumulated.

How much does it snow in December?

In Jefferson, in December, snow falls for 6.8 days, with typically accumulated 3.5" (89mm) of snow.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 6min of daylight.

What is the average length of the day in December?

The average day length in December is 9h and 8min.

What time are sunrise and sunset in December?

On the first day of December, sunrise is at 6:57 am and sunset at 4:15 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:25 pm EST.

How many hours of sunshine does Jefferson have in December?

In December, the average sunshine duration is 4.6h.

When is the lowest UV index?

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index.

What is the UV index reading in December?

In December, the average daily maximum UV index is 2. A UV Index reading of 2, and below, represents a low health risk from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Jefferson, MA

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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 / Average sunshine in December - Jefferson, MA
  • Average daylight in December: 9h and 1min

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 4min

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 - 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 - 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 - 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 - 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).

Jefferson, Massachusetts, USA

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