Temperature in Illinois in August

Daytime highs, nighttime lows and the warmest cities in Illinois, the United States of America this August.

Illinois, the United States of America, a region in the United States of America, experiences maximum daytime temperatures in August ranging from 24°C (75°F) in Roscoe to 31°C (88°F) in Metropolis. Nighttime temperatures generally drop to 20°C (68°F) in Metropolis and 12°C (54°F) in Roscoe. During August, summer is in full swing.

What is the temperature of the different cities in Illinois, the United States of America in August?

Discover the typical August temperatures for the most popular locations of Illinois on the map below. Detailed insights are just a click away.

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Check the conditions for any month of the year.

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For a detailed overview over the year and the best time to visit Illinois, check out our Illinois's climate page.

See also: Illinois weather by month.

Best Places to Visit in Illinois in August

Click on a destination dot for more details. Toggle the map to compare temperatures or precipitation across Illinois.

Conditions Temperatures Precipitation
Avg daytime high -5°C (23°F) cold → 32°C (90°F) hot

Marker color shows the average daytime high temperature in August: blue is cold, red is hot.

See all August weather averages, cities and regions in Illinois

Illinois temperatures in August: frequently asked questions

How hot does it get in Illinois, the United States of America in August?

Chicago averages a daytime high of 28°C (82°F) in August, which is high for Illinois, the United States of America.

How cold does it get at night in Illinois, the United States of America in August?

Average overnight lows in Illinois, the United States of America during August sit near 18°C (64°F) in Chicago.

What is the warmest city in August in Illinois, the United States of America?

Data insights from our comprehensive database indicate that Metropolis is the city with the highest warmth. Daytime peaks average near 31°C (88°F), while the nights are characterized by a low temperature close to 20°C (68°F).

What is the coldest city in August in Illinois, the United States of America?

When looking through our records, we find that Roscoe stands out as the coolest city in Illinois, the United States of America for the month of August. Daytime highs average 24°C (75°F) and it cools down to about 12°C (54°F) at night.

How much sun does Illinois, the United States of America get in August?

Chicago enjoys approximately 280 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.

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