Illinois weather in January
One place stands in for Illinois here — these are Chicago's numbers, not a statewide average.
Based on 1 weather station, in Chicago. One station — Chicago, where Lake Michigan runs the thermostat; downstate summers come hotter, and the far south of the state sees gentler winters.
Chicago & the Lakefront
Highs near 32°, nights around 19°, and 11.3 in of snow in a typical January.
| Place | Highs / lows | Wet days | Snow | The short version |
|---|---|---|---|---|
| Chicago | 32° / 19° | 9 | 11.3 in | Wind off the lake does the real damage — dress for it. |
Each place above has its own page for the full story — what the month feels like, what to pack, and whether the timing is right.