Decatur (IL)
August
Weather in Decatur, Illinois for August 2026
Your guide to Decatur weather in August - trends and predictions
In general, the average temperature in Decatur at the beginning of August is 27.4 °C. As the month progressed, temperatures tended to moderately rise, reaching an average of 29.3 °C by the end of August.
The climate of Decatur in August is notably wet, with an average of 13 rainy days, and a total of 175.5 mm of precipitation.
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Temperatures
Rain 🌧️
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18
Dry days
13
Rainy days
0
Snow days
27°/17°
Temperatures
16 km/h
Avg max wind
76 %
Avg humidity
Decatur Weather August
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Temperatures trend during August in Decatur
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August weather in Decatur day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Aug. 1 |  Thundery outbreaks possible | 29° /20° | 0.1 mm | 7 | |
| Aug. 2 |  Fog | 25° /16° | 0.1 mm | 6 | |
| Aug. 3 |  Patchy rain possible | 27° /16° | 0.4 mm | 6 | |
| Aug. 4 | Patchy rain possible | 27° /18° | 4.4 mm | 6 | |
| Aug. 5 |  Partly cloudy | 28° /19° | 0 mm | 7 | |
| Aug. 6 | Patchy rain possible | 30° /19° | 0 mm | 7 | |
| Aug. 7 | Patchy rain possible | 26° /18° | 0.1 mm | 6 | |
| Aug. 8 | Mist | 28° /18° | 0 mm | 7 | |
| Aug. 9 | Partly cloudy | 27° /17° | 0 mm | 7 | |
| Aug. 10 | Partly cloudy | 27° /16° | 18.6 mm | 7 | |
| Aug. 11 |  Cloudy | 28° /17° | 0 mm | 7 | |
| Aug. 12 | Light rain shower | 26° /18° | 25.7 mm | 6 | |
| Aug. 13 | Patchy rain possible | 26° /16° | 18.5 mm | 6 | |
| Aug. 14 | Mist | 28° /17° | 0 mm | 7 | |
| Aug. 15 |  Moderate or heavy rain shower | 29° /18° | 9.6 mm | 7 | |
| Aug. 16 | Fog | 32° /20° | 5.2 mm | 7 | |
| Aug. 17 | Patchy rain possible | 29° /20° | 2 mm | 7 | |
| Aug. 18 | Fog | 28° /19° | 1.3 mm | 7 | |
| Aug. 19 | Mist | 28° /19° | 77.8 mm | 6 | |
| Aug. 20 | Patchy rain possible | 23° /13° | 0.1 mm | 5 | |
| Aug. 21 | Partly cloudy | 23° /13° | 0 mm | 6 | |
| Aug. 22 |  Overcast | 25° /13° | 0 mm | 6 | |
| Aug. 23 | Partly cloudy | 29° /15° | 0 mm | 7 | |
| Aug. 24 | Partly cloudy | 27° /16° | 0 mm | 7 | |
| Aug. 25 | Light rain shower | 25° /14° | 2.2 mm | 6 | |
| Aug. 26 | Patchy rain possible | 30° /14° | 0.1 mm | 7 | |
| Aug. 27 |  Patchy light rain with thunder | 31° /17° | 0.7 mm | 7 | |
| Aug. 28 |  Sunny | 32° /17° | 0.3 mm | 8 | |
| Aug. 29 | Patchy rain possible | 31° /17° | 1.4 mm | 7 | |
| Aug. 30 | Patchy rain possible | 30° /16° | 4.4 mm | 7 | |
| Aug. 31 | Light rain shower | 26° /17° | 2.6 mm | 6 | |
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Important Notice
Our weather forecast for Decatur 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 Decatur forecast closer to your planned date for the most up-to-date weather information.
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Decatur in August - FAQ
What are the expected maximum and minimum temperatures in Decatur during August?
During August, expect a variety of temperatures with highs around 27° and lows near 17°, suitable for diverse activities and preferences.
How much rainfall should be expected in Decatur during August?
Significant rainfall exceeding 175.5 mm is expected in Decatur during August, occurring over more than 13 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Decatur during August?
The average wind speed in Decatur during August is 16 km/h, suggesting breezy to windy conditions, depending on your activities.
August rainfall patterns in Decatur
Explore the daily rainfall trends and prepare for Decaturs August weather 💧
Typically, Decatur has 13 rainy days in August with a total of 175.5 mm of rainfall.
UV exposure in Decatur during August
Stay informed about UV levels for safe outdoor activities throughout the month of August ☀️
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