December weather forecastMattoon, WI
December
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.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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: 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: 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: 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: 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: 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: 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: 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: 8h and 48min
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 48min
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: 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: 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: 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: 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).
