Fairmount, IL Weather Forecast
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Fairmount Weather Forecast
| TONIGHT | THURSDAY | THURSDAY NIGHT | FRIDAY | FRIDAY NIGHT | SATURDAY | SATURDAY NIGHT | SUNDAY | SUNDAY NIGHT | LABOR DAY | MONDAY NIGHT | TUESDAY |
| Mostly Clear | Sunny | Mostly Clear | Sunny | Partly Cloudy | Chance of Showers | Partly Cloudy | Partly Cloudy | Mostly Clear | Mostly Clear | Partly Cloudy | Partly Cloudy |
| Lo: 75°FLo: 24°C | Hi: 95°FHi: 35°C | Lo: 75°FLo: 24°C | Hi: 91°FHi: 33°C | Lo: 71°FLo: 22°C | Hi: 90°FHi: 32°C | Hi: 85°FHi: 29°C Lo: 69°FLo: 21°C | Hi: 85°FHi: 29°C Lo: 69°FLo: 21°C | Hi: 85°FHi: 29°C Lo: 65°FLo: 18°C | Hi: 85°FHi: 29°C Lo: 65°FLo: 18°C | Hi: 89°FHi: 32°C Lo: 69°FLo: 21°C | Hi: 89°FHi: 32°C Lo: 69°FLo: 21°C |
| POP: 30% |
POP = Probability of Precipitation.
Weather Outlook Updated: 337 PM CDT Wed Sep 02 2026 

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Issued: 150 PM CDT Wed Sep 2 2026
Key Messages
- Extreme Heat: An Extreme Heat Warning is in effect through Friday as high heat and humidity push peak heat index values to around 105F. Highs may exceed 100F (40% to 80% chance) south of a Springfield to Casey line through Friday, with heat indices lingering near 100F into Saturday.
- Isolated Severe Storm Potential: While dry conditions dominate, there is a low risk (under 20% chance) for isolated pop-up afternoon or evening thunderstorm Thursday and Friday. Any storm that develop cou...
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