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City of Decatur, IllinoisDecatur, IL 7-Day Weather Forecast
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Decatur Weather Forecast
Decatur, IL Weather Forecast Date: 1238 AM CDT Mon Aug 17 2026
Weather forecast for Decatur, IL
Tonight Lo: 69°F Lo: 21°C |
Tonight... Cloudy with a chance of showers and thunderstorms. Lows in the upper 60s. Northwest winds around 5 mph. Chance of rain 50%. |
Mon Hi: 81°FHi: 27°C Lo: 61°F Lo: 16°C |
Monday... Mostly sunny. Highs in the lower 80s. North winds 5 to 10 mph. |
| Tue Hi: 81°FHi: 27°C Lo: 69°F Lo: 21°C |
Tuesday... Sunny. Highs in the lower 80s. Southwest winds around 5 mph. |
Wed Hi: 80°FHi: 27°C Lo: 61°F Lo: 16°C |
Wednesday... Showers likely in the morning, then a chance of showers and thunderstorms in the afternoon. Highs around 80. Chance of rain 60%. |
Thu Hi: 79°FHi: 26°C Lo: 61°F Lo: 16°C |
Thursday... Partly sunny. Highs in the upper 70s. |
| Fri Hi: 80°FHi: 27°C Lo: 61°F Lo: 16°C |
Friday... Mostly clear. Highs around 80. Lows in the lower 60s. |
| Sat Hi: 81°FHi: 27°C Lo: 61°F Lo: 16°C |
Saturday... Mostly sunny. Highs in the lower 80s. |
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