December weather forecastChesterfield, IL
December
Weather in December
The first month of the winter, December, is also an icy month in Chesterfield, Illinois, with an average temperature ranging between min 28.8°F (-1.8°C) and max 40.1°F (4.5°C).Temperature
As November transitions into December, Chesterfield sees a drop in the average high-temperature, transitioning from a cool 51.6°F (10.9°C) to an icy 40.1°F (4.5°C). Throughout December, Chesterfield encounters an average temperature drop to a freezing cold 28.8°F (-1.8°C).Humidity
The average relative humidity in December is 78%.Rainfall
In Chesterfield, during December, the rain falls for 8.1 days and regularly aggregates up to 1.3" (33mm) of precipitation. In Chesterfield, during the entire year, the rain falls for 138.2 days and collects up to 23.31" (592mm) of precipitation.Snowfall
January through March, November and December are months with snowfall. In December, it is snowing for 4.7 days. Throughout December, 1.26" (32mm) of snow is accumulated. In Chesterfield, Illinois, during the entire year, snow falls for 21.2 days and aggregates up to 6.65" (169mm) 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 7:01 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 4:47 pm CST.
Sunshine
In Chesterfield, the average sunshine in December is 4.8h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a low health risk from exposure to the Sun's UV radiation for average individuals.Note: A daily maximum UV index of 2 in December translates into the following instructions:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Stay sun-safe with clothing that is both closely woven and worn loosely. Heed this! Snow reflection can almost augment the UV radiation of the sun by double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Chesterfield, IL
- Average high temperature in December: 40.1°F
The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (34.9°F).
- Average low temperature in December: 28.8°F
The month with the highest average low temperature is July (66.9°F).
The coldest month (with the lowest average low temperature) is January (22.5°F).
Average pressure in December
Chesterfield, IL
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Chesterfield, IL
- Average wind speed in December: 9.4mph
The windiest month (with the highest average wind speed) is January (10.1mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).
Average humidity in December
Chesterfield, IL
- Average humidity in December: 78%
The month with the highest relative humidity is July (82%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Chesterfield, IL
- Average rainfall in December: 1.3"
The wettest month (with the highest rainfall) is June (3.07").
The driest months (with the least rainfall) are January and February (1.22").
Average rainfall days in December
Chesterfield, IL
- Average rainfall days in December: 8.1 days
The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is January (6.3 days).
Average snowfall in December
Chesterfield, IL
- Average snowfall in December: 1.26"
The month with the highest snowfall is February (2.28").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Chesterfield, IL
- Average snowfall days in December: 4.7 days
The month with the highest number of snowfall days is February (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
Chesterfield, 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 month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in December
Chesterfield, IL
- Average sunshine days in December: 19.2 days
The month with the most sunshine days is October (19.8 days).
The month with the least sunshine days is May (11.1 days).
Average UV index in December
Chesterfield, 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
Chesterfield, IL
- Average cloud cover in December: 49
The month with the most cloud cover is January (Cloud cover 53).
The months with the least cloud cover are August and September (Cloud cover 29).
Average visibility in December
Chesterfield, 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).





