| WXSIM Forecast for:
O'Fallon Issued by: OFallonweather.com |
||||||||||||||||||||||||||||||||||||||||||||||||
| Updated: Monday, 17-Aug-2026 04:00 pm | ||||||||||||||||||||||||||||||||||||||||||||||||
|
| Tonight |
Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Patchy light fog after midnight. A chance of rain. Low 72°. Wind north around 1 mph, gusting to 22 mph, in the evening, becoming west-northwest after midnight. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch. |
| Tuesday |
Partly cloudy. Patchy light fog in the morning. A chance of rain. Hot. High 89°. Heat index up to 95°. UV index up to 7. Wind southwest around 3 mph, gusting to 23 mph. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch. |
| Tuesday night |
Fair to partly cloudy in the evening, becoming mostly cloudy after midnight. Patchy light fog after midnight. A slight chance of rain in the evening, then a chance of rain after midnight. Precipitation showery or intermittent. Low 73°. Wind east-southeast around 4 mph, gusting to 16 mph, in the evening, becoming south after midnight. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch. |
| Wednesday |
Partly cloudy in the morning, becoming mostly cloudy in the afternoon. Moderate fog in the morning. A chance of rain. Scattered thundershowers possible. High 86°. Heat index up to 92°. UV index up to 6. Wind northeast around 5 mph, gusting to 22 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch. |
| Wednesday night |
Partly cloudy. Patchy light fog in the evening, then light to moderate fog after midnight. A chance of rain. Scattered thundershowers possible. Low 70°. Wind east-northeast around 4 mph, gusting to 18 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch. |
| Thursday |
Mostly cloudy in the morning, becoming partly cloudy in the afternoon. Light to moderate fog in the morning. A chance of rain in the morning, then a slight chance of rain in the afternoon. Precipitation showery or intermittent. High 84°. UV index up to 7. Wind east-northeast around 5 mph, gusting to 22 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch. |
| Thursday night |
Clear. Patchy light fog after midnight. Low 65°. Wind east-northeast around 3 mph, gusting to 18 mph. |
| Friday |
Sunny in the morning, becoming partly to mostly sunny in the afternoon. Patchy light fog in the morning. High 86°. UV index up to 6. Wind east-southeast around 2 mph, gusting to 22 mph, in the morning, becoming east-northeast in the afternoon. |
| Friday night |
Clear. Patchy light fog after midnight. Low 66°. Wind northeast around 2 mph, gusting to 16 mph, in the evening, becoming south-southeast after midnight. |
| Saturday |
Mostly sunny in the morning, becoming partly cloudy in the afternoon. Patchy light fog in the morning. A slight chance of rain. High 86°. UV index up to 6. Wind west-southwest around 3 mph, gusting to 19 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch. |
| Saturday night |
Fair in the evening, becoming mostly clear after midnight. Patchy light fog after midnight. Low 67°. Wind northeast around 3 mph. |
| Sunday |
Mostly sunny in the morning, becoming partly to mostly cloudy in the afternoon. Patchy light fog in the morning. High 86°. UV index up to 6. Wind southeast around 3 mph, gusting to 15 mph, in the morning, becoming 6 mph, gusting to 19 mph, in the afternoon. |
| Sunday night |
Mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Low 70°. Wind southeast around 7 mph, gusting to 17 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