Chicago, Illinois weather in January

Averages from 2021–2025 (155 days of record).

Average high

32°F

Average low

19°F

Rainy days

~10 per month

Total precipitation

2.7 in

Warmest recorded

55°F

Coldest recorded

-13°F

Expect January days in Chicago, Illinois to top out around 32°F and cool to about 19°F overnight, with roughly 10 days of measurable rain across the month. In recent years January has ranged from -13°F to 55°F.