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Illinois United States of America
Temperatures in September
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Temperature in Illinois in September

Illinois is a region in the United States of America. September in has maximum daytime temperatures ranging from pleasant in Roscoe with 21°C to high temperatures in Metropolis with 28°C. Nighttime temperatures generally drop to 15°C in Metropolis and 9°C in Roscoe.

What is the temperature of the different cities in Illinois in September?

Explore the map below to discover average September temperatures at the top destinations in Illinois. For a deeper dive, simply click on any destination dot.

Weather conditions Weather
Temperatures
Precipitation
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Legend very warm warm pleasant moderate cold very cold
Very warm means maximum temperatures above 30°C. Warm: 22°C to 30°C. Pleasant: 18°C to 22°C Moderate: 12°C to 18°C. Cold: 2°C to 12°C. Very cold: lower than 2°C

  • What is the warmest city in September in Illinois?
    • According to our recent database analysis, Metropolis is the warmest city. It experiences an average maximum daytime temperature of approximately 28°C and rarely drops below 15°C during the night.

  • What is the coldest city in September in Illinois?
    • In our database, Roscoe is the chilliest city in September in Illinois. Daytime temperatures typically peak at 21°C, while the nighttime lows hover around 9°C.

  • How much sun does Illinois get in September?
    • Chicago enjoys approximately 226 hours of sunshine, offering a mostly sunny climate that adds a pleasant and vibrant feel to the month.

    Interested in more climate information?

    We have much more information about the climate in Illinois. Interested in the weather conditions in a specific month? Select the month below.

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