December weather forecastWilsonville, IL
December
Weather in December
December, the first month of the winter in Wilsonville, is also an icy month, with an average temperature ranging between min 29.1°F (-1.6°C) and max 40.3°F (4.6°C).Temperature
A moderate decline in the average high-temperature is seen during December, decreasing from a cool 51.6°F (10.9°C) in November to an icy 40.3°F (4.6°C). December nights in Wilsonville, Illinois, are marked by an average low-temperature of 29.1°F (-1.6°C).Humidity
The average relative humidity in December in Wilsonville is 78%.Rainfall
In December, in Wilsonville, Illinois, the rain falls for 6.7 days. Throughout December, 0.87" (22mm) of precipitation is accumulated. Throughout the year, there are 121.4 rainfall days, and 14.72" (374mm) of precipitation is accumulated.Snowfall
January through March, November and December are months with snowfall. The month with the most snowfall is December, when snow falls for 3.8 days and typically aggregates up to 0.98" (25mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 30min of daylight.On the first day of December, sunrise is at 7:00 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:47 pm CST.
Sunshine
The average sunshine in December in Wilsonville is 4.8h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: A daily high UV index of 2 in December leads to these guidelines:
While extended sun exposure does not significantly affect most people, those with sensitive skin, children, and infants should always be protected. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Wilsonville, IL
- Average high temperature in December: 40.3°F
The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (35.6°F).
- Average low temperature in December: 29.1°F
The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).
Average pressure in December
Wilsonville, IL
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Wilsonville, IL
- Average wind speed in December: 9.3mph
The windiest month (with the highest average wind speed) is January (10mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).
Average humidity in December
Wilsonville, IL
- Average humidity in December: 78%
The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Wilsonville, IL
- Average rainfall in December: 0.87"
The wettest month (with the highest rainfall) is June (1.89").
The driest month (with the least rainfall) is February (0.67").
Average rainfall days in December
Wilsonville, IL
- Average rainfall days in December: 6.7 days
The month with the highest number of rainy days is July (14 days).
The month with the least rainy days is January (5.8 days).
Average snowfall in December
Wilsonville, IL
- Average snowfall in December: 0.98"
The month with the highest snowfall is December (0.98").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Wilsonville, IL
- Average snowfall days in December: 3.8 days
The month with the highest number of snowfall days is January (6.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Wilsonville, IL
- Average daylight in December: 9h and 30min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 4h and 48min
The months with the most sunshine are June and July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in December
Wilsonville, IL
- Average sunshine days in December: 20.5 days
The month with the most sunshine days is January (20.9 days).
The month with the least sunshine days is July (12.5 days).
Average UV index in December
Wilsonville, 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).
Average cloud cover in December
Wilsonville, IL
- Average cloud cover in December: 50
The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are June, July, August and September (Cloud cover 29).
Average visibility in December
Wilsonville, IL
- 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).





