| WXSIM Forecast for:
O'Fallon Issued by: OFallonweather.com |
||||||||||||||||||||||||||||||||||||||||||||||||
| Updated: Wednesday, 30-Sep-2026 04:00 pm | ||||||||||||||||||||||||||||||||||||||||||||||||
|
| Tonight |
Mostly cloudy in the evening, becoming partly to mostly cloudy after midnight. Warm. Low 70°. Wind south-southeast around 7 mph, gusting to 20 mph. |
| Thursday |
Mostly cloudy in the morning, becoming cloudy in the afternoon. Patchy light fog in the afternoon. A slight chance of rain in the morning, then rain likely in the afternoon. Warm. High 83°. UV index up to 4. Wind south-southwest around 7 mph, gusting to 22 mph. Chance of precipitation 60 percent. Precipitation mostly between a quarter and half an inch. |
| Thursday night |
Dense overcast. Light to moderate fog in the evening, then patchy light fog after midnight. Rain likely. Mild. Low 65°. Wind northwest around 4 mph in the evening, becoming north around 8 mph, gusting to 22 mph, after midnight. Chance of precipitation 80 percent. Precipitation mostly around an inch. |
| Friday |
Mostly cloudy in the morning, becoming sunny in the afternoon. Patchy light fog in the morning. High 74°. UV index up to 6. Wind north around 9 mph, gusting to 27 mph. |
| Friday night |
Clear. Light to moderate fog after midnight. Low 51°. Wind northeast around 6 mph, gusting to 22 mph. |
| Saturday |
Sunny. Light to moderate fog in the morning. High 72°. UV index up to 6. Wind east-northeast around 5 mph, gusting to 22 mph. |
| Saturday night |
Partly cloudy. Patchy light fog after midnight. Low 52°. Wind east-northeast around 2 mph, gusting to 15 mph. |
| Sunday |
Sunny. Patchy light fog in the morning. High 74°. UV index up to 5. Wind north around 3 mph, gusting to 22 mph. |
| Sunday night |
Clear. Patchy light fog in the evening, then moderate fog after midnight. Low 52°. Wind north around 5 mph. |
| Monday |
Sunny. Moderate fog in the morning. High 72°. UV index up to 5. Wind north-northeast around 5 mph, gusting to 23 mph. |
| Monday night |
Clear in the evening, becoming mostly clear after midnight. Patchy light fog after midnight. Low 49°. Wind northeast around 3 mph in the evening, becoming east after midnight. |
| Tuesday |
Mostly sunny. Patchy light fog in the morning. High 71°. UV index up to 5. Wind east around 6 mph, gusting to 25 mph, in the morning, becoming southeast in the afternoon. |
| Tuesday night |
Mostly cloudy to cloudy in the evening, becoming partly to mostly cloudy after midnight. Low 52°. Wind south-southeast around 5 mph, gusting to 18 mph. |
WXSIM forecast formatting script by Saratoga-Weather.org.