| WXSIM Forecast for:
O'Fallon Issued by: OFallonweather.com |
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| Updated: Tuesday, 29-Sep-2026 05:00 am | ||||||||||||||||||||||||||||||||||||||||||||||||
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| Today |
Sunny in the morning, becoming partly cloudy in the afternoon. Warm. High 79°. UV index up to 6. Wind south-southeast around 3 mph, gusting to 17 mph, in the morning, becoming 7 mph, gusting to 21 mph, in the afternoon. |
| Tonight |
Partly cloudy in the evening, becoming mostly cloudy after midnight. Low 57°. Wind south-southeast around 5 mph. |
| Wednesday |
Mostly cloudy to cloudy in the morning, becoming mostly cloudy in the afternoon. Unusually hot. High 87°. UV index up to 5. Wind south around 7 mph, gusting to 21 mph. |
| Wednesday night |
Partly to mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Warm. Low 67°. Wind south-southeast around 6 mph, gusting to 15 mph. |
| Thursday |
Mostly cloudy in the morning, becoming cloudy in the afternoon. A chance of rain. Scattered thundershowers possible. Unusually hot. High 86°. UV index up to 4. Wind south around 7 mph, gusting to 24 mph, in the morning, becoming southwest in the afternoon. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch. |
| Thursday night |
Cloudy. Patchy light fog in the evening, then light to moderate fog after midnight. A chance of rain in the evening, then rain likely after midnight. Scattered thundershowers possible. Low 64°. Wind north-northeast around 4 mph. Chance of precipitation 80 percent. Precipitation mostly between half an inch and one inch. |
| Friday |
Dense overcast in the morning, becoming partly to mostly cloudy in the afternoon. Light to moderate fog in the morning. Rain likely in the morning, then a slight chance of rain in the afternoon. Precipitation showery or intermittent. High 71°. Wind north around 9 mph, gusting to 25 mph. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch. |
| Friday night |
Clear in the evening, becoming fair to partly cloudy after midnight. Low 52°. Wind northeast around 6 mph, gusting to 22 mph. |
| Saturday |
Partly cloudy. Patchy light fog in the morning. High 73°. UV index up to 5. Wind northeast around 6 mph, gusting to 24 mph. |
| Saturday night |
Fair to partly cloudy. Low 49°. Wind northeast around 3 mph, gusting to 17 mph. |
| Sunday |
Sunny. Patchy light fog in the morning. High 74°. UV index up to 6. Wind north-northeast around 4 mph, gusting to 21 mph. |
| Sunday night |
Clear. Patchy light fog after midnight. Low 48°. Wind north around 5 mph. |
| Monday |
Sunny. Patchy light fog in the morning. High 69°. UV index up to 5. Wind north-northeast around 7 mph, gusting to 24 mph. |
| Monday night |
Clear. Cool. Low 47°. Wind east-northeast around 5 mph, gusting to 18 mph. |
WXSIM forecast formatting script by Saratoga-Weather.org.