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Weather in August in Illinois

Considering a trip to Illinois this August and wondering about the expected weather conditions? Find all the crucial information you need right here, addressing your question:

What is the weather like in Illinois in August?

Illinois is a region in the United States of America. August in Illinois generally has temperatures that range from warm to very warm, with precipitation levels ranging from moderate to high. August falls during the summer season.

Temperatures

The average maximum daytime temperatures vary from warm in Roscoe at 24°C to very warm in Metropolis at 31°C. Nighttime temperatures generally drop to 20°C in Metropolis and 12°C in Roscoe.

Precipitation

In August, precipitation varies across different areas. From moderate rainfall in Tuscola with an average of 63 mm to high rainfall in Monee with 138 mm.

Average sunshine

Meanwhile, Chicago enjoys approximately 280 hours of sunshine, offering a mostly sunny climate that adds a pleasant and vibrant feel to the month.

For specific regional insights in Illinois for August, refer to the map provided below. For an in-depth overview of the yearly weather conditions, do visit our Illinois climate page.

Where to go in Illinois in August

Find more information for the most popular destinations in the Illinois on the map below. Click on a destination dot for more detailes.

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Legend perfect weather pleasant tolerable unpleasant poor
Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C and 29°C and not too much precipitation (less than 90 mm a month).

Popular destinations

What is the weather like in August for the 5 most popular destinations in Illinois?

Chicago

In August Chicago generally has high temperatures with maximum daytime temperatures around 28°C, minimum nighttime temperatures around 18°C and high monthly rainfall. So on average the conditions are pleasant that month.

Chicago
minimum temparatureMax temperature minimum temparatureMax temp
maximum temparatureMin temperature maximum temparatureMin temp
sun hoursMonthly sun hours sun hoursSun hours
precipitationMonthly rainfall precipitationRainfall
rain daysMonthly rainy days rain daysRainy days
conditionsWeather conditions conditionsWeather
<<   July July
<<  
29°C 
19°C 
319 hours 
115 mm 
11 days 
28°C 
18°C 
280 hours 
115 mm 
11 days 
24°C 
14°C 
226 hours 
95 mm 
9 days 
Climate in Chicago

Schaumburg

In August Schaumburg generally has high temperatures with maximum daytime temperatures around 28°C, minimum nighttime temperatures around 17°C and high monthly rainfall. So on average the conditions are pleasant that month.

Schaumburg
minimum temparatureMax temperature minimum temparatureMax temp
maximum temparatureMin temperature maximum temparatureMin temp
sun hoursMonthly sun hours sun hoursSun hours
precipitationMonthly rainfall precipitationRainfall
rain daysMonthly rainy days rain daysRainy days
conditionsWeather conditions conditionsWeather
<<   July July
<<  
29°C 
17°C 
319 hours 
116 mm 
11 days 
28°C 
17°C 
280 hours 
121 mm 
11 days 
24°C 
12°C 
226 hours 
100 mm 
9 days 
Climate in Schaumburg

Rosemont

In August Rosemont generally has high temperatures with maximum daytime temperatures around 28°C, minimum nighttime temperatures around 18°C and high monthly rainfall. So on average the conditions are pleasant that month.

Rosemont
minimum temparatureMax temperature minimum temparatureMax temp
maximum temparatureMin temperature maximum temparatureMin temp
sun hoursMonthly sun hours sun hoursSun hours
precipitationMonthly rainfall precipitationRainfall
rain daysMonthly rainy days rain daysRainy days
conditionsWeather conditions conditionsWeather
<<   July July
<<  
29°C 
19°C 
319 hours 
116 mm 
11 days 
28°C 
18°C 
280 hours 
115 mm 
11 days 
24°C 
14°C 
226 hours 
96 mm 
9 days 
Climate in Rosemont

Joliet

In August Joliet generally has high temperatures with maximum daytime temperatures around 28°C, minimum nighttime temperatures around 17°C and high monthly rainfall. So on average the conditions are pleasant that month.

Joliet
minimum temparatureMax temperature minimum temparatureMax temp
maximum temparatureMin temperature maximum temparatureMin temp
sun hoursMonthly sun hours sun hoursSun hours
precipitationMonthly rainfall precipitationRainfall
rain daysMonthly rainy days rain daysRainy days
conditionsWeather conditions conditionsWeather
<<   July July
<<  
29°C 
18°C 
319 hours 
116 mm 
12 days 
28°C 
17°C 
280 hours 
131 mm 
12 days 
25°C 
13°C 
226 hours 
94 mm 
10 days 
Climate in Joliet

Naperville

In August Naperville generally has high temperatures with maximum daytime temperatures around 28°C, minimum nighttime temperatures around 17°C and high monthly rainfall. So on average the conditions are pleasant that month.

Naperville
minimum temparatureMax temperature minimum temparatureMax temp
maximum temparatureMin temperature maximum temparatureMin temp
sun hoursMonthly sun hours sun hoursSun hours
precipitationMonthly rainfall precipitationRainfall
rain daysMonthly rainy days rain daysRainy days
conditionsWeather conditions conditionsWeather
<<   July July
<<  
29°C 
17°C 
319 hours 
106 mm 
11 days 
28°C 
17°C 
280 hours 
112 mm 
11 days 
25°C 
12°C 
226 hours 
87 mm 
9 days 
Climate in Naperville

Is your destination not in the list? Have a look at other destinations in Illinois, in the United States of America.

Is August the best time to visit Illinois?

In our opinion, August is a good time to visit Illinois with overall pleasant weather in Chicago.

Generally speaking, September provides perfect weather in Chicago. The weather in January, February, March, November and December, on the other hand, tends to be poor.

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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  • Weather and climate has detailed information for every country in the world. Are you going to the United States of America? Get detailed historical weather averages for many cities in the United States of America.

    Not sure yet where to go? We now have a tool which recommends destinations that suit your ideal travel conditions. Find out where to go with our weather planner.