Hottest (avg)
#4 / 12
Chicago in September
September weather, climate averages, and packing tips.
Avg High
Avg Low
Rain
Daylight 12h
What to expect
As autumn continues, September brings, where temperatures are dropping quickly. Daytime highs average 23°C / 74°F, dropping to 16°C / 61°F at night.
Skies are often changeable, and you should be prepared for regular rainfall (approx. 11 wet days).
September in context
How it compares to the rest of the year in Chicago.
Wettest (avg)
#7 / 12
Daylight Hours
#6 / 12
Windiest (avg)
#9 / 12
Highest UV
#6 / 12
Most Humid
#11 / 12
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight
- 12.5 hours
- UV index (max)
- 6
- Typical sun hours
- 05:31 – 17:58
Rain & Snow
- Total
-
- Rainy days
- 11
- Cloud cover
- 47%
- Snowfall
-
Humidity & Wind
- Humidity (avg)
- 70%
- Wind (avg)
-
- Wind (max gusts)
-
Frequently asked questions
Is September a good time to visit Chicago?
Typical September days in Chicago reach highs of 23°C (73°F) with nights around 16°C (61°F). It usually feels warm by day and mild after dark. Overall, September sits in the middle of the Chicago climate range.
What are temperatures like in September?
Daytime temperatures in September typically peak near 23°C (73°F), while nights drop to around 16°C (61°F). Expect warm afternoons and mild evenings.
How much does it rain in September?
Rainfall in September averages 77 mm (3.0 in) across roughly 11 days. Overall it is a quite rainy time of year, so a light rain jacket and waterproof shoes are very handy.
How many hours of daylight are there in September?
You can expect about 12 hours of daylight in September. Sunrise is typically around 05:31 and sunset near 17:58. Daylight is fairly typical, with enough time for sightseeing.
Does the weather change during September?
September usually begins milder and cools down as the month goes on, so late-September can feel more like the next month.
How strong is the sun in September?
UV levels are often high (around 6). Regular sunscreen and a hat are recommended.
Is it windy in September?
In September, average wind speeds are around 14 km/h (9 mph), with gusts on the windiest days reaching about 52 km/h (32 mph). On the ground, it is it can feel quite windy at times, particularly when weather systems move through.