December weather forecast
Mattoon, WI

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Weather in December

December, the first month of the winter in Mattoon, is also a subzero cold month, with an average temperature ranging between max 28.2°F (-2.1°C) and min 18.5°F (-7.5°C).

Temperature

December indicates a shift in the average high-temperature, from November's cold 40.5°F (4.7°C) to a freezing cold 28.2°F (-2.1°C). During the month of December, Mattoon anticipates a mean low-temperature of 18.5°F (-7.5°C).

Humidity

The average relative humidity in December is 85%.

Rainfall

In Mattoon, in December, during 6.3 rainfall days, 1.54" (39mm) of precipitation is typically accumulated. Throughout the year, there are 126.9 rainfall days, and 23.03" (585mm) of precipitation is accumulated.

Snowfall

Months with snowfall in Mattoon, Wisconsin, are January through May, October through December. In December, it is snowing for 11.5 days. Throughout December, 4.57" (116mm) of snow is accumulated. In Mattoon, during the entire year, snow falls for 62 days and aggregates up to 22.2" (564mm) of snow.

Daylight

December has the shortest days of the year, with an average of 8h and 48min of daylight.
On the first day of December in Mattoon, Wisconsin, sunrise is at 7:14 am and sunset at 4:16 pm. On the last day of the month, sunrise is at 7:34 am and sunset at 4:24 pm CST.

Sunshine

In December, the average sunshine in Mattoon is 3.8h.

UV index

The months with the lowest UV index in Mattoon, Wisconsin, are January, November and December, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for ordinary individuals.
Note: In December, a regular UV index of 1 translates into these guidelines:
Extended sunlight exposure does not pose significant problems for most people, except for children, infants, and people with fair skin who always need shielding. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December in Mattoon?

December temperatures vary between a high-temperature of 28.2°F (-2.1°C) and a low-temperature of 18.5°F (-7.5°C).

What is the average humidity in December in Mattoon?

In Mattoon, Wisconsin, the average relative humidity in December is 85%.

How much does it rain in Mattoon in December?

In Mattoon, in December, during 6.3 rainfall days, 1.54" (39mm) of precipitation is typically accumulated.

How much does it snow in Mattoon in December?

In Mattoon, Wisconsin, during December, snow falls for 11.5 days and regularly aggregates up to 4.57" (116mm) of snow.

What is the month with the shortest days in Mattoon?

With an average of 8h and 48min of daylight, December has the shortest days of the year in Mattoon, Wisconsin.

How many hours of daylight does Mattoon have in December?

In December, the average day length is 8h and 50min.

When is the sunrise / sunset in December in Mattoon?

In December, on the first day of the month, sunrise is at 7:14 am and sunset at 4:16 pm. On the last day of the month, in Mattoon, sunrise is at 7:34 am and sunset at 4:24 pm CST.

How long on average sun shines in December in Mattoon?

In Mattoon, Wisconsin, the average sunshine duration in December is 3.8h.

What is the month with the lowest UV index in Mattoon?

The months with the lowest UV index are January, November and December, with an average maximum UV index of 1.

How high is the UV index in December in Mattoon?

The average daily maximum UV index in December in Mattoon is 1. A UV Index of 2, and less, symbolizes 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
Mattoon, WI

Average temperature in December - Mattoon, WI
  • Average high temperature in December: 28.2°F

The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (22.3°F).

  • Average low temperature in December: 18.5°F

The month with the highest average low temperature is July (59°F).
The coldest month (with the lowest average low temperature) is January (11.5°F).

Average pressure in December
Mattoon, WI

Average pressure in December - Mattoon, WI
  • Average pressure in December: 30.07"Hg

The months with the highest atmospheric pressure are February and March (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in December
Mattoon, WI

Average wind speed in December - Mattoon, WI
  • Average wind speed in December: 8.5mph

The windiest month (with the highest average wind speed) is April (9.1mph).
The calmest month (with the lowest average wind speed) is August (6.7mph).

Average humidity in December
Mattoon, WI

Average humidity in December - Mattoon, WI
  • Average humidity in December: 85%

The months with the highest relative humidity are January and February (88%).
The months with the lowest relative humidity are April and May (75%).

Average rainfall in December
Mattoon, WI

Average rainfall in December - Mattoon, WI
  • Average rainfall in December: 1.54"

The wettest month (with the highest rainfall) is May (3.19").
The driest months (with the least rainfall) are January and February (1.02").

Average rainfall days in December
Mattoon, WI

Average rainfall days in December - Mattoon, WI
  • Average rainfall days in December: 6.3 days

The month with the highest number of rainy days is May (15.1 days).
The months with the least rainy days are January and February (4.3 days).

Average snowfall in December
Mattoon, WI

Average snowfall in December - Mattoon, WI
  • Average snowfall in December: 4.57"

The month with the highest snowfall is January (5.28").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Mattoon, WI

Average snowfall days in December - Mattoon, WI
  • Average snowfall days in December: 11.5 days

The month with the highest number of snowfall days is January (15.1 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Mattoon, WI

Average daylight in December / Average sunshine in December - Mattoon, WI
  • Average daylight in December: 8h and 5min

The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).

  • Average sunshine in December: 3h and 5min

The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 3h and 30min).

Average sunshine days in December
Mattoon, WI

Average sunshine days in December - Mattoon, WI
  • Average sunshine days in December: 16.5 days

The month with the most sunshine days is November (16.6 days).
The month with the least sunshine days is April (12.7 days).

Average UV index in December
Mattoon, WI

Average UV index in December - Mattoon, WI
  • Average UV index in December: 1

The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, November and December (UV index 1).

Average cloud cover in December
Mattoon, WI

Average cloud cover in December - Mattoon, WI
  • Average cloud cover in December: 61

The months with the most cloud cover are January and February (Cloud cover 63).
The month with the least cloud cover is July (Cloud cover 33).

Average visibility in December
Mattoon, WI

Average visibility in December - Mattoon, WI
  • Average visibility in December: 6mi

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

Mattoon, Wisconsin, USA

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