Illinois in august: average Weather, Temperature and Climate
Weather in Illinois in august 2025
The weather in Illinois in the month of august comes from statistical datas on the last years. You can view the weather statistics the entire month, but also by using the tabs for the beginning, the middle and the end of the month.
Average weather throughout august
good weather UV index: 6
Weather at 6am
67°F
Fog
36% of time
32%
15%
11%
Weather at 12pm
81°F
Clear/Sunny
51% of time
26%
13%
5%
Weather at 6pm
77°F
Clear/Sunny
59% of time
19%
12%
4%
Weather at 3am
67°F
34%
32%
15%
14%
Evolution of daily average temperature and precipitation in Illinois in august
These charts show the evolution of average minimum/maximum temperatures as well as average daily precipitation volume in Illinois in august.
The climate of Illinois in august is good
the weather in Illinois in august is quite dry (with 3.5in of rainfall over 6 days). Unfortunately, the weather conditions is worsening than the previous month since in july there is an average of 4.5in of precipitation over 7 days.
The climate comfortable in that locality this month. Temperatures are up to 83°F. The minimum is 67°F. Thus, the mean temperature average on this month of august in Illinois is 74°F. Note that these seasonal averages are in contrast with those observed in Illinois in the month of august with a maximum record of 95°F in 2010 and a minimum record of 47°F in 2009. You can expect to have about 6 days with temperatures over 86°F, or 19 of time.
On average, in Illinois, the days of august last 13:46. Sunrise is at 05:09 and sunset is at 18:55.
With good weather conditions, this month is a good time to go in that area.
Seasonal average climate and temperature of Illinois in august
Check below seasonal norms These datas are generated from the weather statements of the last years of the month of august.
| August | |||||
| Outside temperature | |||||
| Average temperature | 74°F | ||||
| Highest temperature | 83°F | ||||
| Lowest temperature | 67°F | ||||
| Highest record temperature | 95°F (2010) | ||||
| Lowest record temperature | 47°F (2009) | ||||
| Number of days at +86°F | 6 day(s) (19%) | ||||
| Number of days at +65°F | 31 day(s) (100%) | ||||
| Wind | |||||
| Wind speed | 14km/h | ||||
| Wind temperature | 67°F | ||||
| Precipitation (rainfall) | |||||
| Rainfall | 3.5in | ||||
| Number of days with rainfall | 6 day(s) (18%) | ||||
| Record daily rainfall | 1.5in (2009) | ||||
| Other climate data | |||||
| Humidity | 93% | ||||
| Visibility | 8.46km | ||||
| Cloud cover | 29% | ||||
| UV index | 6 | ||||
| Daily sunshine hours | 14 | ||||
| Sunrise and sunset | |||||
| Time of sunrise | 05:09 | ||||
| Time of sunset | 18:55 | ||||
| Length of day | 13:46 | ||||
| Our opinion about the weather in august | |||||
| Our opinion at whereandwhen.net | good | ||||
How was the weather last august?
Here is the day by day recorded weather in Illinois in august 2024:
76°F to 90°F
68°F to 77°F
68°F to 86°F
68°F to 85°F
74°F to 88°F
74°F to 85°F
67°F to 79°F
61°F to 76°F
52°F to 68°F
52°F to 74°F
58°F to 79°F
59°F to 65°F
56°F to 77°F
63°F to 81°F
67°F to 85°F
68°F to 85°F
65°F to 74°F
63°F to 79°F
61°F to 79°F
58°F to 74°F
52°F to 74°F
54°F to 76°F
58°F to 83°F
72°F to 86°F
72°F to 81°F
70°F to 94°F
76°F to 101°F
74°F to 90°F
68°F to 92°F
74°F to 94°F
67°F to 85°F
Map: other cities in the United States (USA) in august
Cities near Illinois:
| Chicago in august | good weather |
| St. Louis (Missouri) in august | good weather |
| Indianapolis in august | good weather |
| Wisconsin in august | good weather |
| Missouri in august | good weather |
| Des Moines in august | good weather |
| Louisville (Kentucky) in august | good weather |
| Cincinnati in august | good weather |
| Kansas City in august | good weather |
| Nashville in august | good weather |
| Detroit in august | good weather |
| Minneapolis (Minnesota) in august | perfect weather |
Click over cities on the map for information about the weather in august.
Illinois
perfect weather
good
tolerable
bad
very bad
Weather data for Illinois in august:
Weather data for Illinois for august are derived from an average of the weather forecast since 2009 in Illinois. There is a margin of error and these forecasts are to be considered as general information only. The weather in Illinois can vary slightly from year to year, but this data should limit surprises. So you can pack your bags or check for the best time in year to go to Illinois.