December weather - Winter 2024

Weather in December
Frequently asked questions
Average temperature in December
Average pressure in December
Average wind speed in December
Average humidity in December
Average rainfall in December
Average rainfall days in December
Average snowfall in December
Average snowfall days in December
Average daylight in December
Average sunshine in December
Average sunshine days in December
Average UV index in December
Average cloud cover in December
Average visibility in December

The John Weeks Memorial Footbridge in Cambridge, Massachusetts, over the Charles River calm waters, and a distant view of the Havard University student residence unit

Weather in December

December marks the onset of winter in Cambridge, Massachusetts. White-covered landscapes and Christmas decorations create a picturesque ambiance. The winter chill can be felt, but snowfall remains at the lower end, making travel less challenging. The temperatures drop further across this month with parameters from 29.3°F (-1.5°C) to 39.6°F (4.2°C). Despite the cold, the festive spirit with glowing lights and holiday markets is heart-warming.

Temperature

The shift from November to December corresponds with a decrease in the average high-temperature, down to a wintry 39.6°F (4.2°C) from a chilly 49.5°F (9.7°C). Throughout December, the average low-temperature dips to a freezing cold 29.3°F (-1.5°C).

Humidity

In December, the average relative humidity is 76%.

Rainfall

In Cambridge, in December, during 5.6 rainfall days, 0.55" (14mm) of precipitation is typically accumulated. In Cambridge, during the entire year, the rain falls for 81.8 days and collects up to 5.51" (140mm) of precipitation.

Snowfall

Months with snowfall are January through May, November and December. The month with the most snowfall is December, when snow falls for 2.7 days and typically aggregates up to 0.71" (18mm) 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 December, sunrise is at 6:54 am and sunset at 4:12 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 4:21 pm EST.

Sunshine

The average sunshine in December is 4.9h.

UV index

The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low health risk from exposure to the Sun's UV rays for the ordinary person.
Note: A maximum high UV index of 2 in December translates into the following recommendations:
Prolonged sun exposure generally does not trouble most people. However, it is vital to ensure protection for babies, children, and individuals with sensitive skin. The Sun's radiation is especially intense around midday; try to stay in shade during this period. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.

Updated: Jun 4, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold does it get in December?

In December, the average high-temperature and low-temperature are 39.6°F (4.2°C) and 29.3°F (-1.5°C) respectively. The average heat index (a.k.a. 'feels like', 'real feel'), which calculates the temperature value influenced by the moisture in the air, in July is estimated at 86°F (30°C).

What is the average humidity in December?

The average relative humidity in December is 76%.

How much does it rain in December?

In Cambridge, in December, during 5.6 rainfall days, 0.55" (14mm) of precipitation is typically accumulated.

What is the snowiest month?

December is the month with the most snowfall. Snow falls for 2.7 days and accumulates 0.71" (18mm) of snow.

How much does it snow in December?

In Cambridge, in December, snow falls for 2.7 days, with typically accumulated 0.71" (18mm) of snow.

What is the month with the shortest days?

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

How many hours of daylight does Cambridge have in December?

In December, the average day length is 9h and 8min.

When is the sunrise / sunset in December?

On the first day of December, sunrise is at 6:54 am and sunset at 4:12 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 4:21 pm EST.

How many hours of sunshine does Cambridge have in December?

In Cambridge, the average sunshine duration in December is 4.9h.

When is the lowest UV index?

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

How high is the UV index in December?

In Cambridge, the average daily maximum UV index in December is 2. A UV Index value of 2, and less, symbolizes a minimal hazard to health from unprotected exposure to UV radiation.

Today

Tomorrow

Long-term

Year J F M A M J J A S O N December

Nov

December

Jan

Average high temperature

49.5°F 9.7°C

39.6°F 4.2°C

33.8°F 1°C

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

9.1mph 14.6km/h

9.6mph 15.4km/h

10.1mph 16.3km/h

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

Average daylight

Average sunshine

Average sunshine days

23.3

23.5

Average UV index

Average cloud cover

Average visibility

Average temperature in December
Cambridge, MA

Average high temperature in December: 39.6°F

The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (33.8°F).

Average low temperature in December: 29.3°F

The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (22.5°F).

Average pressure in December
Cambridge, MA

Average pressure in December: 30.03"Hg

The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in December
Cambridge, MA

Average wind speed in December: 9mph

The windiest month (with the highest average wind speed) is January (9.5mph).
The calmest month (with the lowest average wind speed) is August (6mph).

Average humidity in December
Cambridge, MA

Average humidity in December: 76%

The months with the highest relative humidity are January and February (77%).
The month with the lowest relative humidity is April (69%).

Average rainfall in December
Cambridge, MA

Average rainfall in December: 0.55"

The wettest month (with the highest rainfall) is November (0.63").
The driest month (with the least rainfall) is September (0.2").

Average rainfall days in December
Cambridge, MA

Average rainfall days in December: 5.6 days

The month with the highest number of rainy days is July (9.6 days).
The month with the least rainy days is January (4.3 days).

Average snowfall in December
Cambridge, MA

Average snowfall in December: 0.71"

The month with the highest snowfall is December (0.71").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in December
Cambridge, MA

Average snowfall days in December: 2.7 days

The month with the highest number of snowfall days is January (4.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

Average daylight in December /
Average sunshine in December
Cambridge, 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 5min

The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

Average sunshine days in December
Cambridge, MA

Average sunshine days in December: 23 days

The month with the most sunshine days is January (23.5 days).
The month with the least sunshine days is June (17.4 days).

Average UV index in December
Cambridge, 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
Cambridge, MA

Average cloud cover in December: 47

The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 32).

Average visibility in December
Cambridge, MA

Average visibility in December: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

December weather forecast
Cambridge, MA

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