| WXSIM Forecast for:
O'Fallon Issued by: OFallonweather.com |
||||||||||||||||||||||||||||||||||||||||||||||||
| Updated: Sunday, 05-Jul-2026 05:00 am | ||||||||||||||||||||||||||||||||||||||||||||||||
|
| Today |
Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. High 90°. UV index up to 9. Wind north-northwest around 4 mph, gusting to 24 mph. |
| Tonight |
Fair. Relatively cool. Low 66°. Wind north around 4 mph, gusting to 21 mph. |
| Monday |
Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. High 89°. UV index up to 8. Wind north around 6 mph, gusting to 26 mph. |
| Monday night |
Mostly clear in the evening, becoming fair after midnight. Relatively cool. Low 65°. Wind north-northeast around 4 mph, gusting to 23 mph. |
| Tuesday |
Sunny. Hot. High 90°. UV index up to 9. Wind north-northeast around 5 mph, gusting to 25 mph. |
| Tuesday night |
Mostly clear in the evening, becoming fair after midnight. Relatively cool. Low 65°. Wind northeast around 2 mph, gusting to 21 mph, in the evening, becoming southeast after midnight. |
| Wednesday |
Sunny. Hot. High 93°. UV index up to 9. Wind south around 3 mph, gusting to 24 mph, in the morning, becoming west-southwest in the afternoon. |
| Wednesday night |
Clear in the evening, becoming partly cloudy after midnight. Low 68°. Wind south around 4 mph, gusting to 17 mph. |
| Thursday |
Partly to mostly cloudy in the morning, becoming partly cloudy in the afternoon. A chance of rain. Scattered thundershowers possible. Hot. High 93°. Heat index up to 98°. UV index up to 8. Wind southwest around 6 mph, gusting to 23 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch. |
| Thursday night |
Partly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Light to moderate fog in the evening, then moderate fog after midnight. A chance of rain in the evening, then rain likely after midnight. Scattered thundershowers possible. Low 73°. Wind west-northwest around 4 mph, gusting to 17 mph, in the evening, becoming southwest after midnight. Chance of precipitation 70 percent. Precipitation mostly around half an inch. |
| Friday |
Cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. Light to moderate fog in the morning. Rain likely. Scattered thundershowers possible. High 85°. UV index up to 6. Wind west-northwest around 3 mph, gusting to 19 mph. Chance of precipitation 70 percent. Precipitation mostly around a quarter of an inch. |
| Friday night |
Mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Patchy light fog in the evening, then light to moderate fog after midnight. A slight chance of rain in the evening, then rain likely after midnight. Scattered thundershowers possible. Low 73°. Wind south-southeast around 4 mph, gusting to 16 mph, in the evening, becoming east after midnight. Chance of precipitation 80 percent. Precipitation mostly between half an inch and one inch. |
| Saturday |
Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Moderate fog in the morning. A chance of rain in the morning, then a slight chance of rain in the afternoon. Scattered thundershowers possible. Hot. High 91°. Heat index up to 100°. UV index up to 10. Wind south around 7 mph, gusting to 22 mph, in the morning, becoming west-southwest around 12 mph, gusting to 29 mph, in the afternoon. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch. |
| Saturday night |
Partly cloudy in the evening, becoming mostly clear after midnight. Patchy light fog in the evening, then moderate to dense fog after midnight. Low 73°. Wind northwest around 8 mph, gusting to 26 mph, in the evening, becoming 5 mph, gusting to 16 mph, after midnight. |
WXSIM forecast formatting script by Saratoga-Weather.org.