Decatur (IL)
August
Weather in Decatur, Illinois for August 2025
Your guide to Decatur weather in August - trends and predictions
The forecast for the first days of August 2025 in Decatur predicts temperatures to be around 27 °F, close to the historical average.
In general, the average temperature in Decatur at the beginning of August is 26.3 °F. As the month progressed, temperatures tended to significantly warm up, reaching an average of 32.3 °F by the end of August.
Decatur experiences moderate rainfall in August, with an average of 8 rainy days and a total precipitation of 59.5 mm.
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Temperatures
Rain 🌧️
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23
Dry days
8
Rainy days
0
Snow days
27°/17°
Temperatures
17 km/h
Avg max wind
74 %
Avg humidity
Decatur Weather August
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Temperatures trend during August in Decatur
See the weather trend as well as the moving average line
August weather in Decatur day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Aug. 1 |  Partly cloudy | 28° /17° | 0 mm | 2.3 | |
| Aug. 2 |  Sunny | 26° /13° | 0 mm | 2.1 | |
| Aug. 3 | Sunny | 25° /13° | 0 mm | 0 | |
| Aug. 4 | Sunny | 27° /16° | 0 mm | 6 | |
| Aug. 5 |  Patchy rain possible | 23° /20° | 1.4 mm | 5 | |
| Aug. 6 | Patchy rain possible | 26° /18° | 0.1 mm | 5 | |
| Aug. 7 | Partly cloudy | 29° /19° | 0.1 mm | 6 | |
| Aug. 8 | Patchy rain possible | 30° /21° | 0.1 mm | 6 | |
| Aug. 9 | Patchy rain possible | 30° /22° | 3.8 mm | 6 | |
| Aug. 10 | Patchy rain possible | 31° /22° | 0.1 mm | 6 | |
| Aug. 11 |  Thundery outbreaks possible | 30° /20° | 0 mm | 6 | |
| Aug. 12 | Patchy rain possible | 25° /16° | 0.1 mm | 4 | |
| Aug. 13 | Sunny | 21° /9° | 0 mm | 5 | |
| Aug. 14 |  Mist | 27° /16° | 0 mm | 6 | |
| Aug. 15 |  Moderate or heavy rain shower | 29° /19° | 19.3 mm | 6 | |
| Aug. 16 | Fog | 29° /18° | 10.4 mm | 6 | |
| Aug. 17 | Patchy rain possible | 26° /18° | 0.1 mm | 6 | |
| Aug. 18 | Fog | 25° /17° | 0.5 mm | 6 | |
| Aug. 19 | Mist | 26° /15° | 0 mm | 6 | |
| Aug. 20 | Patchy rain possible | 23° /13° | 0.1 mm | 5 | |
| Aug. 21 | Partly cloudy | 22° /10° | 0 mm | 6 | |
| Aug. 22 |  Overcast | 24° /11° | 0 mm | 5 | |
| Aug. 23 | Partly cloudy | 29° /13° | 0 mm | 7 | |
| Aug. 24 | Partly cloudy | 30° /22° | 0 mm | 8 | |
| Aug. 25 | Light rain shower | 27° /20° | 4.4 mm | 6 | |
| Aug. 26 | Patchy rain possible | 34° /21° | 0.2 mm | 7 | |
| Aug. 27 |  Patchy light rain with thunder | 37° /23° | 1.4 mm | 8 | |
| Aug. 28 | Sunny | 35° /23° | 0.7 mm | 9 | |
| Aug. 29 | Patchy rain possible | 33° /21° | 2.7 mm | 7 | |
| Aug. 30 | Patchy rain possible | 35° /20° | 8.7 mm | 8 | |
| Aug. 31 | Light rain shower | 25° /20° | 5.2 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?
Moderate rainfall is anticipated in Decatur during August, with a total of 59.5 mm spread over approximately 8 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Decatur during August?
The average wind speed in Decatur during August is 17 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 💧
UV exposure in Decatur during August
Stay informed about UV levels for safe outdoor activities throughout the month of August ☀️
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