Macon County (Decatur)
September
Weather in Macon County, Illinois for September 2026
Your guide to Macon County weather in September - trends and predictions
So far, September 2026 in Macon County shows a warmer trend than usual by 2.4 °F.
The forecast for the next days in Macon County predicts temperatures to be around 21 °F, close to the historical average.
In general, the average temperature in Macon County at the beginning of September is 28.4 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 20.9 °F by the end of September.
Macon County experiences moderate rainfall in September, with an average of 7 rainy days and a total precipitation of 198.9 mm.
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Temperatures
Rain 🌧️
More
23
Dry days
7
Rainy days
0
Snow days
27°/14°
Temperatures
17 km/h
Avg max wind
65 %
Avg humidity
Macon County Weather September
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Temperatures trend during September in Macon County
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September weather in Macon County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 31° /16° | 0 mm | 7 | |
| Sept. 2 | Sunny | 30° /15° | 0 mm | 7 | |
| Sept. 3 |  Overcast | 29° /16° | 0 mm | 6 | |
| Sept. 4 | Sunny | 30° /15° | 1.7 mm | 7 | |
| Sept. 5 | Sunny | 29° /17° | 0 mm | 7 | |
| Sept. 6 |  Mist | 26° /12° | 0.1 mm | 6 | |
| Sept. 7 | Sunny | 24° /9° | 0 mm | 7 | |
| Sept. 8 | Sunny | 26° /9° | 0 mm | 6 | |
| Sept. 9 | Overcast | 27° /13° | 0 mm | 6 | |
| Sept. 10 | Sunny | 28° /14° | 13.7 mm | 5 | |
| Sept. 11 | Sunny | 31° /15° | 0 mm | 6 | |
| Sept. 12 | Overcast | 31° /16° | 0 mm | 7 | |
| Sept. 13 |  Light rain | 29° /17° | 0.5 mm | 6 | |
| Sept. 14 |  Partly cloudy | 32° /16° | 0 mm | 8 | |
| Sept. 15 |  Patchy rain possible | 33° /20° | 0.9 mm | 6 | |
| Sept. 16 | Sunny | 32° /18° | 3.8 mm | 6 | |
| Sept. 17 |  Cloudy | 31° /17° | 0.1 mm | 7 | |
| Sept. 18 | Sunny | 29° /16° | 2.4 mm | 5 | |
| Sept. 19 | Cloudy | 30° /17° | 3.1 mm | 6 | |
| Sept. 20 | Overcast | 31° /18° | 1.2 mm | 6.9 | |
| Sept. 21 | Overcast | 21° /15° | 3.6 mm | 2.2 | |
| Sept. 22 | Overcast | 17° /14° | 0.1 mm | 3 | |
| Sept. 23 | Overcast | 21° /12° | 0.1 mm | 5.9 | |
| Sept. 24 | Sunny | 22° /12° | 0 mm | 6 | |
| Sept. 25 | Patchy rain possible | 20° /15° | 1.2 mm | 5 | |
| Sept. 26 | Partly cloudy | 23° /14° | 0 mm | 6 | |
| Sept. 27 | Sunny | 25° /14° | 0 mm | 6 | |
| Sept. 28 | Overcast | 17° /10° | 5.4 mm | 4 | |
| Sept. 29 | Sunny | 16° /6° | 0 mm | 5 | |
| Sept. 30 | Sunny | 23° /11° | 0 mm | 6 | |
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Important Notice
Our weather forecast for Macon County in September 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 Macon County forecast closer to your planned date for the most up-to-date weather information.
Change Month
Macon County in September - FAQ
What are the expected maximum and minimum temperatures in Macon County during September?
Enjoy moderate daytime temperatures of up to 27° and cooler nights around 14°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Macon County during September?
Significant rainfall exceeding 198.9 mm is expected in Macon County during September, occurring over more than 7 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Macon County during September?
The average wind speed in Macon County during September is 17 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Macon County
Explore the daily rainfall trends and prepare for Macon Countys September weather 💧
Typically, Macon County has 7 rainy days in September with a total of 198.9 mm of rainfall.
UV exposure in Macon County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is Macon County?Get accurate weather forecasts for Macon County, located at latitude 39.84 and longitude -88.955. Stay updated with localized weather information tailored for Macon County.
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