December weather forecast
Washington, CT

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Weather in December

December, the first month of the winter in Washington, is also an icy month, with an average temperature varying between 26.6°F (-3°C) and 37°F (2.8°C).

Temperature

Transition from November to December is accompanied by a temperature drop, with average high-temperatures decreasing from a chilly 47.1°F (8.4°C) to an icy 37°F (2.8°C). An average temperature of 26.6°F (-3°C) is recorded during the nights in December.

Humidity

In Washington, the average relative humidity in December is 80%.

Rainfall

In Washington, in December, during 10.9 rainfall days, 3.35" (85mm) of precipitation is typically accumulated. Throughout the year, there are 161.7 rainfall days, and 34.41" (874mm) of precipitation is accumulated.

Snowfall

Months with snowfall in Washington are January through May, October through December. In December, in Washington, it is snowing for 6.9 days. Throughout December, 2.95" (75mm) of snow is accumulated. Throughout the year, in Washington, there are 38.3 snowfall days, and 19.84" (504mm) of snow is accumulated.

Daylight

December has the shortest days of the year in Washington, with an average of 9h and 12min of daylight.
On the first day of December, sunrise is at 7:01 am and sunset at 4:23 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 4:33 pm EST.

Sunshine

In Washington, the average sunshine in December is 4.6h.

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 minimal health vulnerability from unsafe exposure to UV radiation for the ordinary person.
Note: The maximum daily UV index of 2 in December converts into the following recommendations:
While most can endure approximately an hour in the sun without burning, children always require protection from sunlight. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Take precaution! The reflection from snow can almost double the UV radiation of the Sun.
Updated: Feb 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in Washington in December?

In Washington, 37°F (2.8°C) is the average high-temperature and 26.6°F (-3°C) is the average low-temperature during December. In July, the average heat index (a.k.a. 'felt air temperature', 'feels like'), which calculates the temperature value influenced by the moisture in the air, is estimated at 87.8°F (31°C).

What is the average humidity in December in Washington?

In December, the average relative humidity is 80%.

How many days does it rain in December in Washington?

In Washington, during December, the rain falls for 10.9 days and regularly aggregates up to 3.35" (85mm) of precipitation.

How many days does it snow in December in Washington?

In Washington, in December, during 6.9 snowfall days, 2.95" (75mm) of snow is typically accumulated.

What is the month with the shortest days in Washington?

December has the shortest days of the year in Washington, with an average of 9h and 12min of daylight.

What is the average length of the day in December in Washington?

The average day length in December in Washington is 9h and 13min.

When is the sunrise / sunset in December in Washington?

On the first day of December in Washington, Connecticut, sunrise is at 7:01 am and sunset at 4:23 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 4:33 pm EST.

How many hours of sunshine does Washington have in December?

In December, the average sunshine duration is 4.6h.

When is the lowest UV index in Washington?

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

How high is the UV index in December in Washington?

The average daily maximum UV index in December in Washington is 2. A UV Index reading of 2, and below, represents a minimal hazard to health 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
Washington, CT

Average temperature in December - Washington, CT
  • Average high temperature in December: 37°F

The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (31.5°F).

  • Average low temperature in December: 26.6°F

The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).

Average pressure in December
Washington, CT

Average pressure in December - Washington, CT
  • Average pressure in December: 30.06"Hg

The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in December
Washington, CT

Average wind speed in December - Washington, CT
  • Average wind speed in December: 7.4mph

The windiest month (with the highest average wind speed) is March (7.9mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).

Average humidity in December
Washington, CT

Average humidity in December - Washington, CT
  • Average humidity in December: 80%

The month with the highest relative humidity is February (81%).
The month with the lowest relative humidity is April (73%).

Average rainfall in December
Washington, CT

Average rainfall in December - Washington, CT
  • Average rainfall in December: 3.35"

The wettest month (with the highest rainfall) is July (3.7").
The driest month (with the least rainfall) is January (2.13").

Average rainfall days in December
Washington, CT

Average rainfall days in December - Washington, CT
  • Average rainfall days in December: 10.9 days

The month with the highest number of rainy days is July (18.3 days).
The month with the least rainy days is January (7.7 days).

Average snowfall in December
Washington, CT

Average snowfall in December - Washington, CT
  • Average snowfall in December: 2.95"

The month with the highest snowfall is February (5.16").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Washington, CT

Average snowfall days in December - Washington, CT
  • Average snowfall days in December: 6.9 days

The month with the highest number of snowfall days is February (10.5 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Washington, CT

Average daylight in December / Average sunshine in December - Washington, CT
  • Average daylight in December: 9h and 1min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in December: 4h and 4min

The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 18min).

Average sunshine days in December
Washington, CT

Average sunshine days in December - Washington, CT
  • Average sunshine days in December: 15.7 days

The month with the most sunshine days is January (17.5 days).
The month with the least sunshine days is June (10.3 days).

Average UV index in December
Washington, CT

Average UV index in December - Washington, CT
  • Average UV index in December: 2

The month with the highest UV index is June (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
Washington, CT

Average cloud cover in December - Washington, CT
  • Average cloud cover in December: 51

The month with the most cloud cover is February (Cloud cover 52).
The months with the least cloud cover are July and August (Cloud cover 37).

Average visibility in December
Washington, CT

Average visibility in December - Washington, CT
  • Average visibility in December: 5mi

The months with the highest visibility are April and November (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October and December (5mi).

Washington, Connecticut, USA

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