| WXSIM Forecast for:
O'Fallon Issued by: OFallonweather.com |
||||||||||||||||||||||||||||||||||||||||||||||||
| Updated: Sunday, 09-Aug-2026 05:00 am | ||||||||||||||||||||||||||||||||||||||||||||||||
|
| Today |
Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. A chance of rain. Hot. High 94°. Heat index up to 102°. UV index up to 8. Wind south-southwest around 5 mph, gusting to 25 mph, in the morning, becoming 8 mph, gusting to 25 mph, in the afternoon. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch. |
| Tonight |
Fair in the evening, becoming fair to partly cloudy after midnight. Patchy light fog after midnight. Low 75°. Wind south-southwest around 6 mph, gusting to 19 mph. |
| Monday |
Partly cloudy. Patchy light fog in the morning. Very hot. High 96°. Heat index up to 108°. UV index up to 8. Wind south-southwest around 8 mph, gusting to 23 mph. |
| Monday night |
Partly cloudy. Patchy light fog after midnight. A chance of rain. Scattered thundershowers possible. Low 76°. Wind south-southwest around 5 mph, gusting to 17 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch. |
| Tuesday |
Mostly sunny in the morning, becoming sunny in the afternoon. Very hot. High 96°. Heat index up to 107°. UV index up to 8. Wind south-southwest around 7 mph, gusting to 25 mph. |
| Tuesday night |
Fair to partly cloudy in the evening, becoming partly cloudy after midnight. Low 74°. Wind south-southwest around 6 mph, gusting to 18 mph. |
| Wednesday |
Partly to mostly sunny. Very hot. High 99°. Heat index up to 107°. UV index up to 9. Wind west-southwest around 6 mph, gusting to 25 mph. |
| Wednesday night |
Partly cloudy in the evening, becoming partly to mostly cloudy after midnight. Patchy light fog after midnight. A slight chance of rain in the evening, then a chance of rain after midnight. Scattered thunderstorms likely. Low 74°. Wind west-northwest around 2 mph, gusting to 16 mph, in the evening, becoming northeast after midnight. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch. |
| Thursday |
Partly to mostly cloudy. Patchy light fog in the morning. A chance of rain in the morning, then a slight chance of rain in the afternoon. Scattered thunderstorms likely. Hot. High 90°. Heat index up to 97°. UV index up to 7. Wind east-northeast around 5 mph, gusting to 22 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch. |
| Thursday 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. Scattered thunderstorms likely. Low 72°. Wind east around 7 mph, gusting to 20 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch. |
| Friday |
Partly to mostly cloudy in the morning, becoming partly cloudy in the afternoon. Light to moderate fog in the morning. A slight chance of rain. Scattered thundershowers possible. Hot. High 90°. Heat index up to 97°. UV index up to 6. Wind east around 5 mph, gusting to 22 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch. |
| Friday night |
Partly cloudy in the evening, becoming mostly cloudy after midnight. A chance of rain in the evening, then a slight chance of rain after midnight. Scattered thundershowers possible. Low 70°. Wind east around 8 mph, gusting to 21 mph. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch. |
| Saturday |
Cloudy in the morning, becoming partly to mostly cloudy in the afternoon. A chance of rain. Precipitation showery or intermittent. High 85°. UV index up to 6. Wind east around 7 mph, gusting to 22 mph. 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 after midnight. Relatively cool. Low 65°. Wind east around 6 mph, gusting to 20 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