Chicago Weather in September
September in Chicago brings high temperatures, with daytime highs of 24°C (75°F) and nights around 14°C (57°F). Quite a bit of rainfall is expected, around 95 mm (3.7 in), so pack an umbrella.
Rainfall in Chicago in September
Analyzing past climate data, one can expect approximately 9 days of rain, averaging 95 mm (3.7 in). Individual showers can be quite heavy this month. A proper umbrella or rain jacket is worth having.
Temperature in Chicago in September
Chicago in September is worth a visit. The temperature is perfect, with 24°C (75°F) during the day and 14°C (57°F) at night. Conditions stay fairly consistent through the month, making it easier to plan what to wear. With lows of 14°C (57°F), nights are cool. If you're out after dark, an extra layer will keep you comfortable. The cooler air at night is also great for getting a good rest.
Sunshine in Chicago in September
Enjoy a sunny month with about 226 hours of sunshine, the clear skies make Chicago even more beautiful.
Wind Speed in Chicago in September
September sees wind speeds averaging 4 m/s (8 knots). You'll experience variable conditions with moderate winds that create small waves on water and keep branches moving. Conditions range from light winds to moderate breezes throughout the month.If you're a fan of comfortable temperatures and drier conditions, September is a great time to visit.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Chicago's climate page.
Chicago Temperature in September
Min Temperature
14°C (57°F)
Max Temperature
24°C (75°F)
Chance of Rain
29%
Precipitation
95 mm (3.7 in)
Rainy days
9 days
Humidity
71%
Windspeed
4 m/s (8 knots)
Sunshine
226 hours
Percentage Sunshine
60%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Chicago typically drop from around 27°C (81°F) at the start of September to approximately 21°C (70°F) by the end. Nights are cool, with lows typically ranging from 11°C (52°F) to 17°C (63°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Chicago in September
Browse day-by-day weather records for Chicago spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Chicago historical weather extremes in September
According to our 49 years of weather records for Chicago, the following extremes were recorded between 1976 and 2025.
- The warmest day in September was on September 7, 1985, with a maximum of 36°C (97°F).
- On September 27, 1984, Chicago saw its coldest September day with temperatures maxing out at 10°C (50°F).
- The lowest overnight temperature recorded in September was -1°C (30°F) (September 23, 1995).
Best Places in the United States of America in September
Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in September →
perfect weather
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What to Wear in Chicago in September
Pleasant temperatures in September mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Prepare for significant rainfall with proper waterproof clothing and shoes. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.What To Do in Chicago in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Chicago's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed
See the full Chicago climate overview or explore weather in the United States of America.
