What to expect in Chicago in September
September is one of the best times to visit Chicago. Expect 24° / 12°, the biggest crowds of the year and prices close to the yearly average.
Chicago weather in September
Typical conditions in Chicago during September, based on long-run climate normals rather than any single year. Treat it as a planning guide, not a forecast.
| Average high | 24°C 75°F |
|---|---|
| Average low | 12°C 54°F |
| Rainfall | Moderate 48/100 |
| Total rainfall | 82 mm3.2 in |
| Rainy days | 8 |
| Daylight | 12 h 30 min |
| How it feels | Warm and comfortable |
Average highs sit around 24°C with lows near 12°C. Rainfall is moderate; the odd shower is likely.
Crowds & demand
Crowd levels are High for Chicago — the biggest crowds of the year.
Prices & value
This month counts as shoulder season: prices close to the yearly average.
What to pack
Light layers for 24°C days and something with sleeves for evenings, which cool to around 12°C.
What it costs
Costs in September sit around the yearly average for Chicago — neither a bargain nor a squeeze. Booking a few weeks out is usually enough. Compared with the most expensive month of the year, you are looking at roughly 21% less.
Who this month suits
- Travellers who want the most reliable weather
- Anyone travelling on a budget
Events & what’s on
No major festivals fall in September, so the destination feels like its everyday self.
Chicago in September compared with nearby months
If your dates are flexible by a few weeks, this is what shifting them actually buys you.
| Month | Temp | Crowds | Price | Score |
|---|---|---|---|---|
| July | 29° / 18° | High | $$$ | 40 |
| August | 28° / 17° | High | $$$ | 42 |
| September · This month | 24° / 12° | High | $$ | 57 |
| October | 17° / 6° | Moderate | $$ | 53 |
| November | 9° / 0° | Moderate | $$ | 51 |
These months score higher for Chicago on the same blend of weather, crowds and price. Same destination, better odds.
Or go somewhere else in September
If the destination is negotiable but the month is not, these places are at their best in September.
Figures are climate normals and modelled estimates — a planning guide, not a forecast. We separate fact, estimate and recommendation. Updated October 2026
