| WXSIM Forecast for:
O'Fallon Issued by: OFallonweather.com |
||||||||||||||||||||||||||||||||||||||||||||||||
| Updated: Wednesday, 19-Aug-2026 05:00 am | ||||||||||||||||||||||||||||||||||||||||||||||||
|
| Today |
Cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. Light to moderate fog in the morning. Rain likely in the morning, then a chance of rain in the afternoon. Scattered thunderstorms likely. High 82°. Wind southeast around 4 mph, gusting to 18 mph, in the morning, becoming east in the afternoon. Chance of precipitation 80 percent. Precipitation mostly around half an inch. |
| Tonight |
Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Patchy light fog in the evening, then light to moderate fog after midnight. A chance of rain in the evening, then a slight chance of rain after midnight. Precipitation showery or intermittent. Low 69°. Wind northeast around 3 mph, gusting to 15 mph. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch. |
| Thursday |
Partly cloudy in the morning, becoming partly to mostly sunny 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. High 83°. UV index up to 7. Wind northeast around 4 mph, gusting to 23 mph. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch. |
| Thursday night |
Fair to partly cloudy in the evening, becoming partly cloudy after midnight. Patchy light fog. A slight chance of rain. Low 67°. Wind northeast around 2 mph, gusting to 17 mph, in the evening, becoming east-southeast after midnight. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch. |
| Friday |
Sunny. Patchy light fog in the morning. High 86°. UV index up to 8. Wind south-southeast around 3 mph, gusting to 20 mph, in the morning, becoming west in the afternoon. |
| Friday night |
Clear in the evening, becoming fair after midnight. Patchy light fog after midnight. Low 69°. Wind west around 2 mph. |
| Saturday |
Sunny in the morning, becoming partly to mostly sunny in the afternoon. Patchy light fog in the morning. High 87°. UV index up to 7. Wind north-northwest around 6 mph, gusting to 24 mph. |
| Saturday night |
Mostly clear in the evening, becoming partly cloudy after midnight. Patchy light fog after midnight. Low 66°. Wind north around 4 mph, gusting to 19 mph. |
| Sunday |
Mostly sunny in the morning, becoming partly cloudy in the afternoon. Patchy light fog in the morning. A slight chance of rain. High 83°. UV index up to 7. Wind northeast around 5 mph, gusting to 24 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch. |
| Sunday night |
Partly cloudy. Light to moderate fog after midnight. A slight chance of rain in the evening, then a chance of rain after midnight. Low 65°. Wind northeast around 4 mph, gusting to 17 mph, in the evening, becoming east-southeast after midnight. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch. |
| Monday |
Partly cloudy. Moderate fog in the morning. High 84°. UV index up to 7. Wind east-southeast around 7 mph, gusting to 25 mph. |
| Monday night |
Mostly clear in the evening, becoming clear after midnight. Light to moderate fog after midnight. Low 63°. Wind east-southeast around 6 mph, gusting to 22 mph. |
| Tuesday |
Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. Light to moderate fog in the morning. High 86°. UV index up to 8. Wind east-southeast around 5 mph, gusting to 22 mph, in the morning, becoming east-northeast in the afternoon. |
| Tuesday night |
Partly to mostly cloudy in the evening, becoming mostly clear after midnight. Low 67°. Wind south around 4 mph in the evening, becoming west after midnight. |
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