Chicago weather in September
Chicago in September averages 20°C (67°F) and 85 mm of rain.
Of the twelve months in Chicago, September is the fourth warmest and the sixth driest.
- Average temp
- 20°C (67°F)
15–25°C · 59–76°F
- Rainfall
- 85 mm
Showers likely
- Sunshine
- —
- Wind
- 13 km/h
What is Chicago like in September?
Daytime
Days are mild.
Rain
Some rain is likely; pack for showers.
Evening
Evenings are cooler. A layer helps after sunset.
What should I pack for Chicago in September?
A light rain jacket
About 85 mm falls this month — showers rather than washouts.
A layer for the evening
Evenings cool off noticeably once the sun is down.
September compared with August and October
September in Chicago is 4°C cooler than August and 19 mm drier than it, which averages 24°C (74°F).
September in Chicago is 6.9°C warmer than October and 13 mm drier than it, which averages 13°C (55°F).
Daylight in Chicago in September
On 15 September the sun is up for 12 hours 28 minutes in Chicago, rising about 06:31 and setting about 18:58 local time.
September ends 1 hour 20 minutes shorter than it begins, so the last week of the month is a different length of day from the first.
That is 2 hours 45 minutes short of June, the longest-lit month here.
Where to stay in Chicago
Dates are a starting point for September.
Travel guides for Chicago
What to read before you book.
Chicago weather by month
TemperatureRainfall
How September compares with the rest of the year
September is highlighted. Every other month links to its own page.
| Month | Average | Rainfall |
|---|---|---|
| January | -3°C / 26°F | 58 mm |
| February | -1°C / 29°F | 54 mm |
| March | 4°C / 39°F | 68 mm |
| April | 10°C / 50°F | 105 mm |
| May | 16°C / 62°F | 121 mm |
| June | 22°C / 72°F | 115 mm |
| July | 25°C / 76°F | 102 mm |
| August | 24°C / 74°F | 104 mm |
| September | 20°C / 67°F | 85 mm |
| October | 13°C / 55°F | 98 mm |
| November | 6°C / 42°F | 69 mm |
| December | 0°C / 31°F | 59 mm |
Similar weather in September
Other destinations whose September averages sit close to this one.
Check another month
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FAQs about Chicago in September
September climate averages for Chicago, 1991–2020.
Chicago averages 20°C (67°F) in September, ranging from about 15°C (59°F) at night to 25°C (76°F) in the afternoon. That is a 1991–2020 average, so an individual week can run either side of it.
Some. About 85 mm falls across September, enough to need a light jacket but not enough to reshape a trip.
Yes. September averages 20°C (67°F) against 13°C (55°F) in October — 6.9°C warmer.
September is 4°C cooler than August, and 19 mm drier.
Yes. September falls inside the most comfortable stretch of the year here, May to October, on temperature and rainfall together.
This page does not show today's weather. It is a 1991–2020 climate normal from Meteostat — a long-run average of what September is usually like, which is what you want when booking months ahead. For today or the coming week, check a live forecast.
About 12 hours 28 minutes of daylight in mid-September, against 15 hours 13 minutes in June and 9 hours 9 minutes in December.
On 15 September, sunrise is about 06:31 and sunset about 18:58 local time. Both shift across the month — the month ends 1 hour 20 minutes shorter than it starts.
