| WXSIM Forecast for:
O'Fallon Issued by: OFallonweather.com |
||||||||||||||||||||||||||||||||||||||||||||||||
| Updated: Tuesday, 02-Jun-2026 04:00 pm | ||||||||||||||||||||||||||||||||||||||||||||||||
|
| Tonight |
Mostly clear. Relatively cool. Low 58°. Wind east around 5 mph, gusting to 24 mph. |
| Wednesday |
Mostly sunny in the morning, becoming sunny in the afternoon. High 83°. UV index up to 9. Wind east around 4 mph, gusting to 24 mph. |
| Wednesday night |
Clear. Relatively cool. Low 57°. Wind east-southeast around 4 mph, gusting to 20 mph, in the evening, becoming south after midnight. |
| Thursday |
Mostly sunny in the morning, becoming partly cloudy in the afternoon. Hot. High 86°. UV index up to 7. Wind south around 6 mph, gusting to 24 mph. |
| Thursday night |
Clear in the evening, becoming fair to partly cloudy after midnight. Relatively cool. Low 60°. Wind south around 7 mph, gusting to 22 mph. |
| Friday |
Cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. A slight chance of rain in the morning, then a chance of rain in the afternoon. Precipitation showery or intermittent. High 82°. UV index up to 5. Wind south around 7 mph, gusting to 21 mph. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch. |
| Friday night |
Partly to mostly cloudy. Light to moderate fog after midnight. A slight chance of rain in the evening, then a chance of rain after midnight. Precipitation showery or intermittent. Low 66°. Wind south-southwest around 4 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch. |
| Saturday |
Partly to mostly cloudy. Light to moderate fog in the morning. A chance of rain. Scattered thundershowers possible. High 85°. UV index up to 7. Wind southwest around 8 mph, gusting to 24 mph. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch. |
| Saturday night |
Mostly cloudy to cloudy. Patchy light fog. A chance of rain in the evening, then a slight chance of rain after midnight. Scattered thundershowers possible. Low 70°. Wind south-southwest around 3 mph, gusting to 16 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch. |
| Sunday |
Mostly cloudy to cloudy in the morning, becoming cloudy in the afternoon. Patchy light fog in the morning, then light to moderate fog in the afternoon. A chance of rain in the morning, then rain likely in the afternoon. Scattered thundershowers possible. High 77°. UV index up to 5. Wind east-southeast around 5 mph, gusting to 16 mph. Chance of precipitation 70 percent. Precipitation mostly between a quarter and half an inch. |
| Sunday night |
Cloudy in the evening, becoming dense overcast after midnight. Light to moderate fog. Rain very likely. Scattered thunderstorms likely. Low 70°. Wind east-southeast around 5 mph. Chance of precipitation 80 percent. Precipitation mostly between half an inch and one inch. |
| Monday |
Dense overcast. Light to moderate fog. Rain very likely. Scattered thundershowers possible. High 75°. Wind east-southeast around 6 mph, gusting to 15 mph. Chance of precipitation 80 percent. Precipitation mostly between half an inch and one inch. |
| Monday night |
Dense overcast. Light to moderate fog in the evening, then patchy light fog after midnight. A chance of rain in the evening, then a slight chance of rain after midnight. Precipitation showery or intermittent. Low 71°. Wind east-southeast around 6 mph, gusting to 16 mph. Chance of precipitation 50 percent. Precipitation mostly around a tenth of an inch. |
WXSIM forecast formatting script by Saratoga-Weather.org.