Chicago Weather in December
The first substantial snowfalls of winter usually arrive in December at Chicago, Illinois. This is also when temperatures begin to drop below 10 °F (-12 °C).
This page gives detailed information on the typical December weather for Chicago.
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The numbers here are historical averages based on climate data gathered at the Chicago O'Hare International Airport, located in the northwestern part of Chicago.
|35 °F||December average high||2 °C|
|21 °F||December average low||-6 °C|
In most years, Chicago averages a daily maximum temperature for December that's between 29 and 40 degrees Fahrenheit (-2 to 5 degrees Celsius). The minimum temperature usually falls between 15 and 27 °F (-10 to -3 °C).
The days at Chicago continue to grow colder during December. By the end of the month, the temperature has dropped around 8 °F (5 °C) below what it was at the start.
|9 days||40 °F max. or more (4 °C)|
|13 days||20 °F min. or less (-8 °C)|
Chicago averages 3 days this month when the thermometer reaches into the 50s °F (over 10 °C). Temperatures above 60 °F (16 °C) don't happen every year in December. Typically 11 days remain below freezing for the entire day.
Most December nights are below freezing. The thermometer drops to 10 °F (-12 °C) or lower on 6 nights. On average, one or two nights in December go down to 0 °F (-18 °C) or colder.
|2.3 in||total precipitation||57 mm|
|11 days||of rain or snowfall|
Half the time, Chicago receives 1 to 3 inches (30 to 70 mm) of precipitation in December. One in four years has drier weather, while another one in four is wetter.
|8.5 in||total snowfall||21.6 cm|
|7 days||with new snow|
December's snowfall varies a lot from year to year in Chicago. Between 3 and 11 inches (8 to 27 cm) of fresh snow arrives in half the years. Less new snow lands in one out of four Decembers, while another twenty-five percent are snowier.
Chicago typically has at least an inch (2.5 cm) of snow on the ground for 10 days this month. The snow normally accumulates to 5 inches (13 cm) or deeper on 2 days.
|6 days||clear skies|
The sun's rays reach the ground in Chicago during 43 percent of daylight hours on average in December, for a total of 123 hours in the month. Typically on 6 days this month the sky is mainly clear, with at most 30 percent cloud cover.
Sunlight in December at Chicago averages 9 hours and 11 minutes a day. The shortest days of the year, from around December 18th to 24th, last 9 hours and 8 minutes from sunrise to sunset.
|76 %||December average humidity|
December is Chicago's most humid month. The relative humidity usually peaks at 80 percent in the morning then drops to 68 percent by early afternoon.
|Local Time||12 am||3 am||6 am||9 am||12 pm||3 pm||6 pm||9 pm|
|11.0 mph||December wind speed average||17.7 kph|
December is a little windier than most other months in Chicago.
|3 days||snowfall of 1 inch (2.5 cm) or more|
|1 day||with thunderstorms in December|
Every few years, Chicago can get 5 to 10 inches (13 to 25 mm) of snow in one day during December.
Thunderstorms don't show up every year in December.
These weather data are long-term historical averages provided by the National Climatic Data Center of the United States. The temperature and precipitation numbers are 1981-2010 normals while the humidity and thunderstorm statistics are 1961-1990 normals.