December weather forecastWilmette, IL
December
Weather in December
December, the first month of the winter in Wilmette, is also a wintry month, with an average temperature varying between 35.4°F (1.9°C) and 27.5°F (-2.5°C).Temperature
In December, the meteorological conditions alter, with the average high-temperature shifting from a frosty 45.9°F (7.7°C) in November to a wintry 35.4°F (1.9°C). Wilmette upholds a consistent average temperature of 27.5°F (-2.5°C) throughout the nights of December.Humidity
In December, the average relative humidity is 80%.Rainfall
The month with the least rainfall in Wilmette is December, when the rain falls for 7.9 days and typically collects 1.38" (35mm) of precipitation.Snowfall
Months with snowfall in Wilmette are January through April, October through December. In December, in Wilmette, it is snowing for 8 days. Throughout December, 2.05" (52mm) of snow is accumulated. In Wilmette, Illinois, during the entire year, snow falls for 40.5 days and aggregates up to 12.76" (324mm) of snow.Daylight
The month with the shortest days in Wilmette is December, with an average of 9h and 12min of daylight.On the first day of the month, sunrise is at 7:00 am and sunset at 4:20 pm. On the last day of December, sunrise is at 7:19 am and sunset at 4:29 pm CST.
Sunshine
In Wilmette, the average sunshine in December is 4h.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for the average person.Note: The maximum daily UV index, 1 in December, converts into the following recommendations:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded 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. Opt for tightly woven and loose clothing to enhance protection from the Sun. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Wilmette, IL
- Average high temperature in December: 35.4°F
The warmest month (with the highest average high temperature) is August (77°F).
The month with the lowest average high temperature is January (29.1°F).
- Average low temperature in December: 27.5°F
The months with the highest average low temperature are July and August (68°F).
The coldest month (with the lowest average low temperature) is January (20.5°F).
Average pressure in December
Wilmette, IL
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Wilmette, IL
- Average wind speed in December: 11.9mph
The windiest month (with the highest average wind speed) is January (12.7mph).
The calmest months (with the lowest average wind speed) are July and August (8mph).
Average humidity in December
Wilmette, IL
- Average humidity in December: 80%
The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is October (73%).
Average rainfall in December
Wilmette, IL
- Average rainfall in December: 1.38"
The wettest month (with the highest rainfall) is June (4.49").
The driest month (with the least rainfall) is December (1.38").
Average rainfall days in December
Wilmette, IL
- Average rainfall days in December: 7.9 days
The month with the highest number of rainy days is July (17.3 days).
The month with the least rainy days is February (5.6 days).
Average snowfall in December
Wilmette, IL
- Average snowfall in December: 2.05"
The month with the highest snowfall is January (3.58").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Wilmette, IL
- Average snowfall days in December: 8 days
The month with the highest number of snowfall days is January (11.6 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
Wilmette, IL
- Average daylight in December: 9h and 12min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 4h and 0min
The months with the most sunshine are July and August (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in December
Wilmette, IL
- Average sunshine days in December: 15.3 days
The month with the most sunshine days is December (15.3 days).
The months with the least sunshine days are June and July (10.9 days).
Average UV index in December
Wilmette, IL
- Average UV index in December: 1
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Wilmette, IL
- Average cloud cover in December: 59
The month with the most cloud cover is January (Cloud cover 62).
The months with the least cloud cover are July and August (Cloud cover 27).
Average visibility in December
Wilmette, 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).





