December weather forecastDarien, IL
December
Weather in December
The first month of the winter, December, is still a cold month in Darien, Illinois, with an average temperature fluctuating between 25°F (-3.9°C) and 34.5°F (1.4°C).Temperature
Onset of December witnesses a reduction in the average high-temperature, falling from a chilly 45.7°F (7.6°C) in November to a cold 34.5°F (1.4°C). December witnesses an average nighttime temperature of 25°F (-3.9°C).Humidity
In Darien, the average relative humidity in December is 81%.Rainfall
December is the month with the least rainfall. Rain falls for 4.9 days and accumulates 0.63" (16mm) of precipitation.Snowfall
Months with snowfall are January through April, October through December. In Darien, in December, during 7.2 snowfall days, 0.75" (19mm) of snow is typically accumulated. In Darien, during the entire year, snow falls for 34.9 days and aggregates up to 7.2" (183mm) of snow.Daylight
December has the shortest days of the year, 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 4:22 pm. On the last day of December, sunrise is at 7:18 am and sunset at 4:31 pm CST.
Sunshine
In Darien, Illinois, the average sunshine in December is 4.1h.UV index
In December, the average daily maximum UV index is 2. A UV Index of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV rays for the average person.Note: The average daily UV index of 2 in December transforms into the following instructions:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. During bright days, sunglasses that offer UVA and UVB defense are recommended. Take warning! The intensity of the Sun's UV radiation can be nearly amplified twice due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Darien, IL
- Average high temperature in December: 34.5°F
The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in December: 25°F
The month with the highest average low temperature is July (66.4°F).
The coldest month (with the lowest average low temperature) is January (17.1°F).
Average pressure in December
Darien, IL
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Darien, IL
- Average wind speed in December: 9mph
The windiest month (with the highest average wind speed) is January (9.7mph).
The calmest month (with the lowest average wind speed) is August (6.1mph).
Average humidity in December
Darien, IL
- Average humidity in December: 81%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (72%).
Average rainfall in December
Darien, IL
- Average rainfall in December: 0.63"
The wettest month (with the highest rainfall) is May (1.97").
The driest month (with the least rainfall) is December (0.63").
Average rainfall days in December
Darien, IL
- Average rainfall days in December: 4.9 days
The month with the highest number of rainy days is May (14.9 days).
The month with the least rainy days is February (4.2 days).
Average snowfall in December
Darien, IL
- Average snowfall in December: 0.75"
The month with the highest snowfall is February (2.28").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Darien, IL
- Average snowfall days in December: 7.2 days
The month with the highest number of snowfall days is January (9.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Darien, 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 6min
The month with the most sunshine is August (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Darien, IL
- Average sunshine days in December: 20.7 days
The month with the most sunshine days is December (20.7 days).
The month with the least sunshine days is July (11.8 days).
Average UV index in December
Darien, IL
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in December
Darien, IL
- Average cloud cover in December: 59
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in December
Darien, 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).





