December weather forecastCharleston, IL
December
Weather in December
December, the first month of the winter in Charleston, is also an icy month, with an average temperature fluctuating between 28.8°F (-1.8°C) and 39°F (3.9°C).Temperature
December involves a decrease in temperature, down from a frosty 49.8°F (9.9°C) in November to a wintry 39°F (3.9°C). Charleston records an average low-temperature of 28.8°F (-1.8°C) throughout the month of December.Humidity
In December, the average relative humidity is 79%.Rainfall
In Charleston, during December, the rain falls for 9.4 days and regularly aggregates up to 1.57" (40mm) of precipitation. Throughout the year, there are 148 rainfall days, and 25.63" (651mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, October through December. The month with the most snowfall is December, when snow falls for 6 days and typically aggregates up to 2.13" (54mm) of snow.Daylight
With an average of 9h and 24min of daylight, December has the shortest days of the year in Charleston.On the first day of December, sunrise is at 6:54 am and sunset at 4:29 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 4:39 pm CST.
Sunshine
In Charleston, the average sunshine in December is 4.4h.UV index
With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index reading of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: The daily maximum UV index of 1 in December interprets into the following advice:
Sun exposure does not present considerable issues for many, yet infants, fair-skinned people, and children necessitate constant protection. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses. Observe! Snow reflection can nearly intensify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Charleston, IL
- Average high temperature in December: 39°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (34°F).
- Average low temperature in December: 28.8°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (21.9°F).
Average pressure in December
Charleston, 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 (29.93"Hg).
Average wind speed in December
Charleston, IL
- Average wind speed in December: 9.9mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest month (with the lowest average wind speed) is July (6.2mph).
Average humidity in December
Charleston, IL
- Average humidity in December: 79%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (70%).
Average rainfall in December
Charleston, IL
- Average rainfall in December: 1.57"
The wettest month (with the highest rainfall) is April (3.31").
The driest month (with the least rainfall) is February (1.3").
Average rainfall days in December
Charleston, IL
- Average rainfall days in December: 9.4 days
The month with the highest number of rainy days is May (16.8 days).
The month with the least rainy days is February (7.8 days).
Average snowfall in December
Charleston, IL
- Average snowfall in December: 2.13"
The month with the highest snowfall is December (2.13").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Charleston, IL
- Average snowfall days in December: 6 days
The month with the highest number of snowfall days is January (8.1 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
Charleston, IL
- Average daylight in December: 9h and 24min
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 24min).
- Average sunshine in December: 4h and 24min
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 0min).
Average sunshine days in December
Charleston, IL
- Average sunshine days in December: 16.9 days
The month with the most sunshine days is October (18.3 days).
The month with the least sunshine days is July (10.6 days).
Average UV index in December
Charleston, 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
Charleston, IL
- Average cloud cover in December: 54
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is June (Cloud cover 31).
Average visibility in December
Charleston, IL
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
