The highest day temperature in December 2025 was 52°F. The lowest night temperature was -5°F. The average values for day and night temperatures during December were 29.5°F и 20.6°F respectivly.

The average sea surface temperature in December 2025 for Chicago was 37.3°F. The maximum and minimum values were 32.8°F and 44.2°F respectively.

Most of the days in December are gloomy but you can also expect sunny days.

Precipitation total in December for Chicago is 1.5 in. It makes december one of the least rainy months of the year.

The average wind speed in December is 11.5 mph.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Chicago in December is 3.9 hours.