Weather In Chicago December 2024. The outside temperature in chicago feels like 1.8°c. Daily low temperatures decrease by 8°f, from 32°f to 24°f, rarely falling.

Average air temperature in chicago is 4.5°c (40.1°f) in december. A shift in chicago’s weather is observed as november turns into december, with the average high temperature reducing from a frosty 46°f (7.8°c) to a cold 35.8°f (2.1°c).