| WXSIM Forecast for:
O'Fallon Issued by: OFallonweather.com |
||||||||||||||||||||||||||||||||||||||||||||||||
| Updated: Monday, 22-Jun-2026 04:00 pm | ||||||||||||||||||||||||||||||||||||||||||||||||
|
| Tonight |
Partly cloudy in the evening, becoming clear after midnight. Patchy light fog after midnight. Unusually cool. Low 56°. Wind north around 4 mph, gusting to 19 mph. |
| Tuesday |
Sunny. Patchy light fog in the morning. High 81°. UV index up to 8. Wind north around 4 mph, gusting to 22 mph, in the morning, becoming east-northeast in the afternoon. |
| Tuesday night |
Fair to partly cloudy in the evening, becoming partly cloudy after midnight. Unusually cool. Low 58°. Wind east-southeast around 4 mph, gusting to 17 mph. |
| Wednesday |
Partly to mostly 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. Thunderstorms very likely, some possibly severe. High 79°. UV index up to 5. Wind south around 6 mph, gusting to 22 mph, in the morning, becoming southwest in the afternoon. Chance of precipitation 50 percent. Precipitation mostly less than a tenth of an inch. |
| Wednesday night |
Fair to partly cloudy in the evening, becoming mostly cloudy after midnight. Patchy light fog. A chance of rain. Scattered thunderstorms likely. Relatively cool. Low 65°. Wind southwest around 3 mph, gusting to 17 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch. |
| Thursday |
Partly cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. Patchy light fog. A slight chance of rain in the morning, then rain likely in the afternoon. Thunderstorms very likely, some possibly severe. High 86°. UV index up to 7. Wind south-southeast around 3 mph, gusting to 22 mph. Chance of precipitation 80 percent. Precipitation mostly between a quarter and half an inch. |
| Thursday night |
Dense overcast in the evening, becoming cloudy after midnight. Light to moderate fog. Rain. Thunderstorms very likely, some possibly severe. Low 71°. Wind southeast around 3 mph. Chance of precipitation near 100 percent. Precipitation mostly around an inch. |
| Friday |
Dense overcast. Light to moderate fog. Rain. Thunderstorms very likely, some possibly severe. Relatively cool. High 75°. Wind south-southeast around 6 mph, gusting to 16 mph. Chance of precipitation near 100 percent. Precipitation mostly between 1 and 2 inches. |
| Friday night |
Mostly cloudy to cloudy in the evening, becoming partly to mostly cloudy after midnight. Light to moderate fog in the evening, then moderate fog after midnight. Rain likely in the evening, then a slight chance of rain after midnight. Scattered thunderstorms likely. Low 70°. Wind south-southwest around 6 mph, gusting to 16 mph, in the evening, becoming northwest after midnight. Chance of precipitation 70 percent. Precipitation mostly around a quarter of an inch. |
| Saturday |
Partly to mostly cloudy. Light to moderate fog in the morning. A chance of rain. Scattered thunderstorms likely. High 87°. Heat index up to 93°. UV index up to 9. Wind northwest around 5 mph, gusting to 22 mph, in the morning, becoming southwest in the afternoon. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch. |
| Saturday night |
Mostly cloudy in the evening, becoming partly cloudy after midnight. Patchy light fog in the evening, then moderate fog after midnight. A chance of rain in the evening, then rain likely after midnight. Thunderstorms very likely, some possibly severe. Low 72°. Wind east-southeast around 5 mph, gusting to 20 mph. Chance of precipitation 70 percent. Precipitation mostly around a quarter of an inch. |
| Sunday |
Sunny. Moderate to dense fog in the morning. A chance of rain. Scattered thunderstorms likely. Hot. High 94°. Heat index up to 104°. UV index up to 10. Wind south-southwest around 10 mph, gusting to 26 mph. Chance of precipitation 50 percent. Precipitation mostly around a quarter of an inch. |
| Sunday night |
Clear. Patchy light fog in the evening, then moderate fog after midnight. Low 74°. Wind south-southwest around 6 mph, gusting to 19 mph. |
WXSIM forecast formatting script by Saratoga-Weather.org.
Powered by Davis Vantage Pro2
and
CumulusMX
v 4.6.4 (b4128)
MXUI Template v 2.2.6 by
Silver Acorn
Valid HTML5