December weather forecastCahokia, IL
December
Weather in December
December, the first month of the winter in Cahokia, is still a chilly month, with an average temperature varying between 42.8°F (6°C) and 30.6°F (-0.8°C).Temperature
December's arrival corresponds with a decrease in average high-temperatures, from November's fresh 53.2°F (11.8°C) to a frosty 42.8°F (6°C). Cahokia experiences an average temperature drop to a freezing cold 30.6°F (-0.8°C) during December nights.Humidity
The average relative humidity in December in Cahokia, Illinois, is 76%.Rainfall
In Cahokia, in December, it is raining for 8.4 days, with typically 2.4" (61mm) of accumulated precipitation. In Cahokia, during the entire year, the rain falls for 152.2 days and collects up to 36.46" (926mm) of precipitation.Snowfall
January through March, November and December are months with snowfall in Cahokia. In December, in Cahokia, it is snowing for 4 days. Throughout December, 1.5" (38mm) of snow is accumulated. In Cahokia, during the entire year, snow falls for 20.2 days and aggregates up to 7.44" (189mm) of snow.Daylight
With an average of 9h and 30min of daylight, December has the shortest days of the year.On the first day of December in Cahokia, sunrise is at 7:00 am and sunset at 4:40 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:49 pm CST.
Sunshine
In December, the average sunshine in Cahokia is 4.8h.UV index
January, February and December, with an average maximum UV index of 2, are months with the lowest UV index in Cahokia. A UV Index reading of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum UV index of 2 during December leads to these instructions:
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 radiation is especially intense around midday; try to stay in shade during this period. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Cahokia, IL
- Average high temperature in December: 42.8°F
The warmest month (with the highest average high temperature) is July (86.4°F).
The month with the lowest average high temperature is January (37.8°F).
- Average low temperature in December: 30.6°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (24.6°F).
Average pressure in December
Cahokia, 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
Cahokia, IL
- Average wind speed in December: 8.6mph
The windiest month (with the highest average wind speed) is January (9.3mph).
The calmest month (with the lowest average wind speed) is July (5.5mph).
Average humidity in December
Cahokia, IL
- Average humidity in December: 76%
The months with the highest relative humidity are May and July (78%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Cahokia, IL
- Average rainfall in December: 2.4"
The wettest month (with the highest rainfall) is May (4.53").
The driest month (with the least rainfall) is February (2.01").
Average rainfall days in December
Cahokia, IL
- Average rainfall days in December: 8.4 days
The month with the highest number of rainy days is May (17.4 days).
The month with the least rainy days is January (7.7 days).
Average snowfall in December
Cahokia, IL
- Average snowfall in December: 1.5"
The month with the highest snowfall is February (2.44").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Cahokia, IL
- Average snowfall days in December: 4 days
The month with the highest number of snowfall days is January (6.4 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
Cahokia, IL
- Average daylight in December: 9h and 30min
The month with the longest days is June (Average daylight: 14h and 48min).
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 24min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in December
Cahokia, IL
- Average sunshine days in December: 18.4 days
The month with the most sunshine days is October (18.7 days).
The month with the least sunshine days is May (10.7 days).
Average UV index in December
Cahokia, IL
- Average UV index in December: 2
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February and December (UV index 2).
Average cloud cover in December
Cahokia, IL
- Average cloud cover in December: 49
The month with the most cloud cover is January (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in December
Cahokia, 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).
