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O'Fallon Weather Forecast
| REST OF TONIGHT | WEDNESDAY | WEDNESDAY NIGHT | THURSDAY | THURSDAY NIGHT | FRIDAY | FRIDAY NIGHT | SATURDAY | SUNDAY | SUNDAY NIGHT | MONDAY | MONDAY NIGHT |
 |  |  |  |  | | |  | |  | | |
| Chance of Rain | Mostly Cloudy | Clearing | Sunny | Mostly Cloudy | Partly Sunny | Partly Cloudy | Partly Cloudy | Sunny | Clear | Sunny | Clear |
| Lo: 55°FLo: 13°C | Hi: 61°FHi: 16°C | Lo: 45°FLo: 7°C | Hi: 65°FHi: 18°C | Lo: 45°FLo: 7°C | Hi: 59°FHi: 15°C | Hi: 55°FHi: 13°C Lo: 35°FLo: 2°C | Hi: 55°FHi: 13°C Lo: 35°FLo: 2°C | Hi: 61°FHi: 16°C | Lo: 35°FLo: 2°C | Hi: 65°FHi: 18°C | Lo: 41°FLo: 5°C |
| POP: 50% |
POP = Probability of Precipitation.
Weather Outlook Updated: 1228 AM CST Wed Nov 04 2026 
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Issued: 1059 PM CST Tue Nov 3 2026
Key Messages
- Showers and isolated thunderstorms will exit the area this evening. A marginal risk for severe thunderstorms remains in place for much of the area, with confidence in these severe storms developing the greatest in NE MO and west-central IL.
- A pair of cold fronts will move through the area tonight and again on Thursday, dropping temperatures to near seasonal normals by the weekend.
Aviation
/00Z TAFS THROUGH 06Z THURSDAY/... Issued at 1059 PM CST Tue Nov 3 2026
A cold front is moving thr...