December weather forecast
Washington, IL

Weather in December

December, the first month of the winter in Washington, is still a cold month, with an average temperature ranging between max 36.5°F (2.5°C) and min 25.9°F (-3.4°C).

Temperature

In December, the average high-temperature drops from a frosty 47.7°F (8.7°C) in November to a wintry 36.5°F (2.5°C). The average low-temperature, in December, is 25.9°F (-3.4°C).

Humidity

The average relative humidity in December in Washington, Illinois, is 80%.

Rainfall

In Washington, it is raining for 6.1 days, with typically 0.98" (25mm) of accumulated precipitation. In Washington, during the entire year, the rain falls for 128.3 days and collects up to 19.13" (486mm) of precipitation.

Snowfall

January through April, November and December are months with snowfall in Washington. In December, it is snowing for 5.5 days. Throughout December, 1.18" (30mm) of snow is accumulated. Throughout the year, in Washington, there are 29.2 snowfall days, and 9.13" (232mm) of snow is accumulated.

Daylight

With an average of 9h and 19min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 7:02 am and sunset at 4:31 pm. On the last day of the month, sunrise is at 7:21 am and sunset at 4:39 pm CST.

Sunshine

The average sunshine in December is 4.4h.

UV index

The months with the lowest UV index in Washington are January, February, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for average individuals.
Note: The average daily UV index of 2 in December transform into the following instructions:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
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FAQ

What is the temperature in December in Washington?

In December, in Washington, the average high-temperature is 36.5°F (2.5°C), and the average low-temperature is 25.9°F (-3.4°C). The average heat index (a.k.a. 'feels like', 'apparent temperature'), which combines air temperature and relative humidity, in August is estimated at 86°F (30°C).

What is the average humidity in December in Washington?

In December, the average relative humidity is 80%.

How much does it rain in Washington in December?

In December, in Washington, the rain falls for 6.1 days. Throughout December, 0.98" (25mm) of precipitation is accumulated.

How many days does it snow in December in Washington?

In Washington, Illinois, during December, snow falls for 5.5 days and regularly aggregates up to 1.18" (30mm) of snow.

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 19min of daylight.

How many hours of daylight does Washington have in December?

In Washington, Illinois, the average day length in December is 9h and 19min.

When are sunrise and sunset in December in Washington?

In December, on the first day of the month, sunrise is at 7:02 am and sunset at 4:31 pm. On the last day of the month, in Washington, Illinois, sunrise is at 7:21 am and sunset at 4:39 pm CST.

How long on average sun shines in December in Washington?

In December, the average sunshine duration is 4.4h.

What are the months with the lowest UV index in Washington?

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

How high is the UV index in December in Washington?

In December, the average daily maximum UV index is 2. A UV Index of 2, and less, symbolizes a minimal hazard to health from unsafe exposure to Sun's UV rays.
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, IL

Average temperature in December - Washington, IL
  • Average high temperature in December: 36.5°F

The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (30.6°F).

  • Average low temperature in December: 25.9°F

The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (18.5°F).

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Average pressure in December
Washington, IL

Average pressure in December - Washington, IL
  • Average pressure in December: 30.11"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

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Average wind speed in December
Washington, IL

Average wind speed in December - Washington, IL
  • Average wind speed in December: 9.9mph

The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).

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Average humidity in December
Washington, IL

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

The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (71%).

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Average rainfall in December
Washington, IL

Average rainfall in December - Washington, IL
  • Average rainfall in December: 0.98"

The wettest month (with the highest rainfall) is May (2.6").
The driest month (with the least rainfall) is November (0.94").

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Average rainfall days in December
Washington, IL

Average rainfall days in December - Washington, IL
  • Average rainfall days in December: 6.1 days

The month with the highest number of rainy days is July (16.4 days).
The month with the least rainy days is January (4.4 days).

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Average snowfall in December
Washington, IL

Average snowfall in December - Washington, IL
  • Average snowfall in December: 1.18"

The month with the highest snowfall is January (2.68").
The months with the least snowfall are May, June, July, August, September and October (0").

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Average snowfall days in December
Washington, IL

Average snowfall days in December - Washington, IL
  • Average snowfall days in December: 5.5 days

The month with the highest number of snowfall days is January (10.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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

Average daylight in December / Average sunshine in December - Washington, IL
  • Average daylight in December: 9h and 2min

The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in December: 4h and 2min

The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).

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Average sunshine days in December
Washington, IL

Average sunshine days in December - Washington, IL
  • Average sunshine days in December: 20.5 days

The month with the most sunshine days is December (20.5 days).
The month with the least sunshine days is July (11.4 days).

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Average UV index in December
Washington, IL

Average UV index in December - Washington, IL
  • 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, November and December (UV index 2).

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Average cloud cover in December
Washington, IL

Average cloud cover in December - Washington, IL
  • Average cloud cover in December: 53

The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 30).

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Average visibility in December
Washington, IL

Average visibility in December - Washington, IL
  • Average visibility in December: 6mi

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

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