Illinois (Chicago)
August
Weather in Illinois for August 2025
Your guide to Illinois weather in August - trends and predictions
In general, the average temperature in Illinois at the beginning of August is 26.9 °F. As the month progressed, temperatures tended to moderately rise, reaching an average of 27.6 °F by the end of August.
Illinois in August brings notable rainfall, with an average of 19 rainy days and a total precipitation of 78.8 mm.
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Temperatures
Rain 🌧️
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12
Dry days
19
Rainy days
0
Snow days
26°/20°
Temperatures
18 km/h
Avg max wind
69 %
Avg humidity
Illinois in August average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  28° | 2  26° | 3 28° | ||||
| 4  26° | 5 27° | 6 26° | 7 27° | 8 28° | 9 25° | 10 27° |
| 11 27° | 12 26° | 13 26° | 14  25° | 15  24° | 16 26° | 17 25° |
| 18 25° | 19 27° | 20 26° | 21 24° | 22 26° | 23 29° | 24  30° |
| 25 29° | 26 27° | 27 29° | 28 28° | 29 28° | 30 26° | 31 26° |
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Temperatures trend during August in Illinois
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August weather day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Aug. 1 | Moderate rain at times | 28° /20° | 3.5 mm | 6 | |
| Aug. 2 | Cloudy | 26° /20° | 0.8 mm | 6 | |
| Aug. 3 | Cloudy | 28° /20° | 2.4 mm | 6 | |
| Aug. 4 | Patchy rain possible | 26° /20° | 0.3 mm | 6 | |
| Aug. 5 | Patchy rain possible | 27° /20° | 2 mm | 6 | |
| Aug. 6 | Moderate or heavy rain shower | 26° /20° | 7 mm | 6 | |
| Aug. 7 | Moderate rain at times | 27° /20° | 4.4 mm | 6 | |
| Aug. 8 | Moderate or heavy rain shower | 28° /19° | 3.6 mm | 6 | |
| Aug. 9 | Moderate or heavy rain shower | 25° /18° | 4.3 mm | 6 | |
| Aug. 10 | Patchy rain possible | 27° /17° | 0.8 mm | 7 | |
| Aug. 11 | Patchy rain possible | 27° /19° | 1.5 mm | 6 | |
| Aug. 12 | Cloudy | 26° /19° | 2.3 mm | 6 | |
| Aug. 13 | Patchy rain possible | 26° /19° | 0.9 mm | 6 | |
| Aug. 14 | Sunny | 25° /19° | 6.6 mm | 6 | |
| Aug. 15 | Partly cloudy | 24° /18° | 3.4 mm | 5 | |
| Aug. 16 | Sunny | 26° /18° | 4 mm | 6 | |
| Aug. 17 | Patchy rain possible | 25° /19° | 5.6 mm | 6 | |
| Aug. 18 | Patchy rain possible | 25° /19° | 0.4 mm | 6 | |
| Aug. 19 | Patchy rain possible | 27° /19° | 0.2 mm | 6 | |
| Aug. 20 | Patchy rain possible | 26° /20° | 4 mm | 7 | |
| Aug. 21 | Moderate or heavy rain shower | 24° /19° | 1 mm | 6 | |
| Aug. 22 | Sunny | 26° /19° | 0.2 mm | 6 | |
| Aug. 23 | Sunny | 29° /19° | 0 mm | 7 | |
| Aug. 24 | Heavy rain at times | 30° /20° | 0.3 mm | 7 | |
| Aug. 25 | Patchy rain possible | 29° /21° | 5.1 mm | 6 | |
| Aug. 26 | Cloudy | 27° /20° | 0.8 mm | 6 | |
| Aug. 27 | Patchy rain possible | 29° /20° | 0 mm | 7 | |
| Aug. 28 | Moderate or heavy rain shower | 28° /20° | 5.9 mm | 7 | |
| Aug. 29 | Moderate or heavy rain shower | 28° /20° | 3.1 mm | 6 | |
| Aug. 30 | Cloudy | 26° /20° | 4.2 mm | 6 | |
| Aug. 31 | Partly cloudy | 26° /18° | 0.2 mm | 7 | |
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Important Notice
Our weather forecast for Illinois in August is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Illinois forecast closer to your planned date for the most up-to-date weather information.
Illinois in August - FAQ
What are the expected maximum and minimum temperatures in Illinois during August?
During August, expect a variety of temperatures with highs around 26° and lows near 20°, suitable for diverse activities and preferences.
How much rainfall should be expected in Illinois during August?
Moderate rainfall is anticipated in Illinois during August, with a total of 78.8 mm spread over approximately 19 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Illinois during August?
The average wind speed in Illinois during August is 18 km/h, suggesting breezy to windy conditions, depending on your activities.
August rainfall patterns in Illinois
Explore the daily rainfall trends and prepare for Illinoiss August weather 💧
UV exposure in Illinois during August
Stay informed about UV levels for safe outdoor activities throughout the month of August ☀️
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