| WXSIM Forecast for:
O'Fallon Issued by: OFallonweather.com |
||||||||||||||||||||||||||||||||||||||||||||||||
| Updated: Monday, 18-May-2026 04:00 pm | ||||||||||||||||||||||||||||||||||||||||||||||||
|
| Tonight |
Partly to mostly cloudy. A chance of rain. Scattered thundershowers possible. Low 63°. Wind south around 10 mph, gusting to 15 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch. |
| Tuesday |
Mostly cloudy to cloudy in the morning, becoming dense overcast in the afternoon. A slight chance of rain in the morning, then a chance of rain in the afternoon. Thunderstorms very likely, some severe. High 78°. UV index up to 4. Wind south-southwest around 9 mph, gusting to 24 mph, in the morning, becoming west-southwest in the afternoon. Chance of precipitation 60 percent. Precipitation mostly less than a quarter of an inch. |
| Tuesday night |
Dense overcast in the evening, becoming cloudy after midnight. Patchy light fog. Rain likely. Thunderstorms very likely, some possibly severe. Low 60°. Wind north-northwest around 7 mph, gusting to 21 mph. Chance of precipitation 60 percent. Precipitation mostly less than a quarter of an inch. |
| Wednesday |
Mostly cloudy to cloudy in the morning, becoming mostly cloudy in the afternoon. High 72°. UV index up to 6. Wind north-northeast around 9 mph, gusting to 27 mph. |
| Wednesday night |
Partly to mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Cool. Low 54°. Wind north-northeast around 7 mph, gusting to 24 mph. |
| Thursday |
Partly to mostly cloudy in the morning, becoming cloudy in the afternoon. High 70°. UV index up to 6. Wind east-northeast around 7 mph, gusting to 24 mph. |
| Thursday night |
Mostly cloudy to cloudy in the evening, becoming cloudy after midnight. Cool. Low 53°. Wind east-northeast around 7 mph, gusting to 21 mph. |
| Friday |
Dense overcast. Rain likely. Scattered thundershowers possible. Cool. High 62°. Wind east-northeast around 5 mph in the morning, becoming east-southeast in the afternoon. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch. |
| Friday night |
Cloudy in the evening, becoming mostly cloudy after midnight. A slight chance of rain. Precipitation showery or intermittent. Low 56°. Wind east-northeast around 3 mph in the evening, becoming north-northeast after midnight. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch. |
| Saturday |
Partly to mostly cloudy in the morning, becoming cloudy in the afternoon. A chance of rain. High 71°. UV index up to 4. Wind northwest around 5 mph, gusting to 19 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch. |
| Saturday night |
Mostly cloudy to cloudy. A slight chance of rain in the evening, then a chance of rain after midnight. Low 57°. Wind north-northeast around 3 mph in the evening, becoming south-southwest after midnight. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch. |
| Sunday |
Cloudy. A chance of rain. Scattered thundershowers possible. High 73°. UV index up to 4. Wind south around 3 mph in the morning, becoming 7 mph, gusting to 18 mph, in the afternoon. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch. |
| Sunday night |
Dense overcast. 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 64°. Wind south around 6 mph, gusting to 18 mph. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch. |
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