This post is an overview of the September weather in Chicago, including snow and precipitation forecasts, as well as tips on how to dress and things to do.
If you'll be in town either before or after the month, make sure to check our posts on weather in August and October.
- Temperatures
- How Much Sun, Rain and Snow
- What to Wear
- Things to Do
- Seasonal Outlook
- Free Tours by Foot
HOW COLD IS CHICAGO IN SEPTEMBER?
This month turns out to be a very pleasant month as far as temperatures, with less rainy days than in August.
The long summer days are behind us now. Often the thermometer will reach over 60 °F (16 °C) in Chicago, with an average high of 75 °F (24 °C) and low of 54 °F (12 °C).

HOW MUCH SUN AND RAIN?
In September, the city experiences less wind and less rain!
There is a steep decline in stormy weather after the summer thunderstorms of August, and rainfall only adds up to 3.2 inches (82 mm) of rain over the course of about 8 rainy days.
The sun shines for an average of 12 hours and 27 minutes a day, with about 9 clear days throughout the month.
The average humidity during August is 71%, with the mornings reaching up to 85% humidity, and letting up throughout the day to around 55%

WHAT TO WEAR IN SEPTEMBER?
Chicago in September can be a little unpredictable, and you will want to reflect that in your wardrobe.
Be sure to still pack comfortable, light-weight clothing for the warmer days and hours of this month, especially in the early days of September.
The temperatures begin to cool during the evening hours, as well as later in the month, so you will want to be prepared with layers.

Sunblock and comfortable walking shoes are still essential this month, as there are many great outdoor activities and beautiful parts of the city to explore with our walking tours.
Throw a water bottle in as well, so you can stay hydrated during your Chicago adventure.
WHAT TO DO IN CHICAGO IN SEPTEMBER?
Below are the top things to do in September in Chicago.
But, be sure to read our full post on what to do in Chicago in September which includes free things to do, night and family-friendly activities and attractions, as well as our definitive post on the best things to do in Chicago.
And if you are planning on visiting many of Chicago's top attractions, then you should consider a tourist discount pass as you could save up to 50% of retail ticket prices to tours, attractions, and restaurants.
Be sure to check out all the top things to do in September in our main post.
Seasonal Outlook
July to September 2022 Chicago
There is a 75% chance for normal to above normal temperatures with near normal rainfall.
Fred Pickhardt
Ocean Weather Services