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Mattoon, KY Weather Forecast
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Mattoon Weather Forecast
| OVERNIGHT | TUESDAY | TUESDAY NIGHT | WEDNESDAY | WEDNESDAY NIGHT | THURSDAY | FRIDAY | SATURDAY | SUNDAY | SUNDAY NIGHT | MONDAY |
 |  | | | | | | | |  |  |
| Clear | Sunny | Mostly Clear | Sunny | Mostly Clear | Mostly Clear | Mostly Clear | Mostly Clear | Mostly Sunny | Chance of Showers | Chance of Showers |
| Lo: 69°FLo: 21°C | Hi: 95°FHi: 35°C | Lo: 75°FLo: 24°C | Hi: 95°FHi: 35°C | Lo: 71°FLo: 22°C | Hi: 95°FHi: 35°C Lo: 71°FLo: 22°C | Hi: 95°FHi: 35°C Lo: 71°FLo: 22°C | Hi: 95°FHi: 35°C Lo: 71°FLo: 22°C | Hi: 90°FHi: 32°C | Lo: 65°FLo: 18°C | Hi: 81°FHi: 27°C |
| POP: 30% | POP: 40% |
POP = Probability of Precipitation.
Weather Outlook Updated: 117 AM CDT Tue Sep 15 2026 
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Issued: 1110 PM CDT Mon Sep 14 2026
Key Messages
- A dangerous late season heat wave with high temperatures near or at record levels will begin today and continue through most of the week.
- A Heat Advisory will be in effect this afternoon through Wednesday evening for the entire area. The Heat Advisory may need to be extended to Thursday or Friday as well.
- Cooler and less humid conditions will arrive Sunday and Monday, along with a 20 to 40% chance of showers and thunderstorms on both days.
Discussion
... Issued at 1052 PM CDT Mon Sep 1...