Verdict: Excellent month
Chicago Weather in September
September hits the sweet spot in Chicago — highs around 24°C (75°F), ideal for a full day on foot. Rain is occasional — about 8 wet days in a typical year. Overall, September is one of the best months of the year to be in Chicago.
Average high
24°C / 75°F
Average low
16°C / 61°F
Rain days
~8
Precipitation
98 mm
What to pack for Chicago in September
- Summer clothes, plus one light layer for air-con and evenings
- A packable rain shell or compact umbrella earns its space
- Comfortable walking shoes — every guide on this site assumes you'll use them
September against the rest of the year
Warmest in Chicago: Jul (27°C / 81°F) · Coolest: Jan (1°C / 34°F) · Wettest: Apr (~15 rain days)
1°
-6°
Jan
3°
-6°
Feb
9°
0°
Mar
14°
4°
Apr
19°
10°
May
26°
17°
Jun
27°
19°
Jul
27°
19°
Aug
24°
16°
Sep
17°
9°
Oct
10°
3°
Nov
4°
-2°
Dec
Daily highs / lows in °C · bars show rain days per month · ERA5 climate normals (2020–2024)