Illinois weather in September 2022

  • 24°C maximum daytime temperature in September in Illinois (Chicago)24
    24°C max day temperature
  • 8 hours of sunshine per day
  • 9 days with some rainfall in September in Illinois (Chicago)9
    9 days with some rainfall
  • 12°C minimum night-time temperature in September in Illinois (Chicago)12
    12°C min night temperature
  • 12 hours of daylight per day in September in Illinois (Chicago)12
    12 hours of daylight per day
  • No heat & humidity in September in Illinois (Chicago)0
    No heat & humidity
  • 87 mm monthly rainfall in September in Illinois (Chicago)87
    87 mm of monthly rainfall
  • UV (maximum) index 6 (High) in September in Illinois (Chicago)6
    6 (High) UV index
  • 19°C sea temperature in September in Illinois (Chicago)19
    19°C sea temperature

Below are average maximum temperatures at popular destinations in Illinois in September. Select a destination to see more weather parameters.

More destinations >>

  • Save EXTRA 10% on cheap car hire worldwide
  • With this exclusive Holiday Autos discount code
  • Travel before 31st December 2021 (inclusive)
Show discount codeShow discount code ******vel

Expires at 23:59 on Saturday 31st Dec 2022 · View all Holiday Autos offers

Holiday AutosCar hire finder

Recommended for Illinois

The September weather guide for Illinois (Chicago) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

  • Top deals & discounts
  • Illinois weather overview
  • Illinois climate averages by month
  • More destinations
  • Best time to go to Illinois
  • Illinois 5-day weather forecast

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Metric (°C / mm)  |  Imperial (°F / inches)

Back to top

More about the USA

How hot is it in Illinois in September?

Daytime temperatures usually reach 24°C in Chicago, Illinois in September, falling to 12°C at night.

How sunny is it in Illinois in September?

There are normally 8 hours of bright sunshine each day in Chicago, Illinois in September - that's 61% of daylight hours.

How warm is the sea around Illinois in September?

The average sea temperature around Chicago, Illinois in September is 19°C.

Does it rain in Illinois in September?

There are usually 9 days with some rain in Chicago, Illinois in September and the average monthly rainfall is 87mm.

Illinois September sunrise & sunset times

Browse the sunrise and sunset times for Illinois in September 2022. Select a month to view Illinois sunrise and sunset times for the next 12 months. The Illinois sunrise and sunset times shown below are for Chicago.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Thursday, 1st September 2022 06:16 19:24
Thursday, 15th September 2022 06:31 19:00
Friday, 30th September 2022 06:46 18:34

Related posts

Popular travel offers

Top ^

*affiliate links: find out how we are funded and why this helps us remain free to use.