Climate averages 1991–2020
Chicago weather
in December.
A cold, moderately wet month: the 10th warmest and the 2nd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cold month in Chicago: daytime highs average 2.2°C and nights cool to about -3.5°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 61 mm of rain on roughly 9 days, which makes December a moderately wet month (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 9 h 12 min on an average December day.
The nearest other city in this atlas is Cicero (9 km away). In December its highs average 2.3°C, about as warm as Chicago, with 61 mm of rain.
Among the 498 cities listed in the United States, Chicago ranks joint 439th of 498 for the warmest December highs and joint 219th of 498 for the driest December (rainfall, lowest first). The mean December high of those 498 cities is 10.5°C; Chicago is 8.3°C cooler than that mean.
From December to January, average highs fall by 3.0°C to -0.7°C, and monthly precipitation rises from 61 mm to 62 mm.
The annual picture
December in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Chicago climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -0.7°C-7.4°C | -7.4°C | 62 | 9.1 | 9.510 h |
| February | 0.9°C-6.5°C | -6.5°C | 54 | 7.6 | 10.611 h |
| March | 6.0°C-1.6°C | -1.6°C | 71 | 10.3 | 11.912 h |
| April | 12.3°C4.4°C | 4.4°C | 114 | 12.4 | 13.313 h |
| May | 18.7°C10.9°C | 10.9°C | 110 | 12.4 | 14.515 h |
| June | 24.6°C17.2°C | 17.2°C | 102 | 12.1 | 15.215 h |
| July | 27.3°C20.2°C | 20.2°C | 92 | 11.5 | 14.915 h |
| August | 26.4°C19.7°C | 19.7°C | 95 | 10.9 | 13.914 h |
| September | 22.7°C15.8°C | 15.8°C | 75 | 8.8 | 12.513 h |
| October | 15.9°C9.2°C | 9.2°C | 85 | 9.5 | 11.111 h |
| November | 8.4°C2.4°C | 2.4°C | 72 | 9.0 | 9.910 h |
| December, selected | 2.2°C-3.5°C | -3.5°C | 61 | 8.7 | 9.29 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Cicero in DecemberUnited States · 9 kmHigh 2.3°C · Low -4.0°C · 61 mm rain
- Evanston in DecemberUnited States · 22 kmHigh 2.0°C · Low -3.0°C · 59 mm precipitation
- Hammond in DecemberUnited States · 32 kmHigh 2.5°C · Low -3.3°C · 58 mm rain
- Arlington Heights in DecemberUnited States · 38 kmHigh 1.8°C · Low -4.4°C · 54 mm precipitation
- Gary in DecemberUnited States · 38 kmHigh 2.5°C · Low -2.9°C · 60 mm rain
- Bolingbrook in DecemberUnited States · 39 kmHigh 2.1°C · Low -4.8°C · 55 mm rain
- Schaumburg in DecemberUnited States · 41 kmHigh 1.7°C · Low -5.2°C · 54 mm precipitation
- Naperville in DecemberUnited States · 42 kmHigh 2.1°C · Low -4.9°C · 55 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Chicago) is explained once on the Chicago year overview and on the Sources, method and limits page.
Cicero lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.