Measurements:
°C
°F
Chicago
0°F
N 9 mph
Feels like: -14°F
Precip: 0%
World Resorts USA Chicago Weather September Weather in Chicago

Chicago Weather: September

Average Day Temperature: 75.6°F
Average Night Temperature: 65.4°F
Sea Water Temperature: 67.9°F
Number of Sunny Days: 17 days
Sunshine Hours: 11.8 - 13.1 hours
Number of Rainy Days: 4 days
Precipitation Totals: 2.3 in

Air Temperature in September, °F

Select Year: 2025 2024 2023

The highest day temperature in September 2025 was 91°F. The lowest night temperature was 52°F. The average values for day and night temperatures during September were 78.9°F и 63.7°F respectivly.

Chicago Water Sea Temperature in September, °F

Select Year: 2025 2024 2023

The average sea surface temperature in September 2025 for Chicago was 66.7°F. The maximum and minimum values were 60.0°F and 72.4°F respectively.

Sunny, Cloudy and Gloomy days

Most of the days in September are sunny but you can also expect cloudy and gloomy days.

Precipitation Totals in September, in

Precipitation total in September for Chicago is 2.3 in.

Wind Speed in September, mph

The average wind speed in September is 9.2 mph. It makes September one of the most windless months of the year for Chicago.

Average Sunny Hours Per Day

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Chicago in September is 8.4 hours.

Best Time to Visit Chicago
The most sunny months:
September 17 days
August 16 days
July 15 days
The most warm months:
July 83.8 °F
August 83.2 °F
June 77.0 °F
Warmest sea temperature:
August 72.5 °F
July 70.2 °F
September 67.9 °F
The most cold months:
January 25.8 °F
February 28.7 °F
December 34.4 °F
The most rainy months:
June 7 days
May 6 days
July 5 days
The most windy months:
November 12 mph
January 12 mph
February 11 mph

Chicago on the Weather Map

USA Resorts:
NAME
Chicago 0
Hawaii +78
Honolulu +78
Houston +46
Las Vegas +40
Los Angeles +52
Maui +72
Miami +72
Miami Beach +80
New York +18
San Diego +54
San Francisco +46
Sarasota +62
Tampa +62
Washington +28
24 Hours Weather Forecast
Chicago
Local time: 01:20
05 dec, friday
0300 -2°F
NE
9 mph
0600 0°F
NE
9 mph
0900 14°F
NE
11 mph
1200 20°F
NE
12 mph
1500 28°F
NE
12 mph
1800 28°F
NE
14 mph
2100 28°F
NE
13 mph
06 dec, saturday
0000 26°F
NE
11 mph