OFallon Missouri Weather

OFallon - Weather Data from OFallon, MO

Latitude: N 38° 50' 20" Longitude: W 90° 43' 42" Altitude: 532 ft

CDT UTC Last station update CDT

WXSIM Forecast for: O'Fallon
Issued by: OFallonweather.com

Updated: Saturday, 30-May-2026 04:00 pm

Tonight Thunder storm	Sunday Thunder storm	Sunday night Thunder storm	Monday Thunder storm	Monday night Fog late	Tuesday Fog a.m.	Tuesday night Mostly Clear	Wednesday Sunny
<.1 in.	<.1 in.	<.1 in.	<.1 in.
Low: 66°	High: 85°	Low: 63°	High: 84°	Low: 63°	High: 82°	Low: 58°	High: 83°

E 6-17 mph	ESE 6-25 mph	ESE 4-19 mph	SE→NE 3-23 mph	NNE 4-18 mph	ENE 8-26 mph	E 7-23→4 mph	E 5-25 mph
	UV: 8 Very High		UV: 6 High		UV: 7 High		UV: 9 Very High

Tonight	Mostly cloudy in the evening, becoming cloudy after midnight. A slight chance of rain. Scattered thunderstorms likely. Low 66°. Wind east around 6 mph, gusting to 17 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.
Sunday	Partly to mostly cloudy in the morning, becoming partly cloudy in the afternoon. A slight chance of rain. Scattered thunderstorms likely. High 85°. UV index up to 8. Wind east-southeast around 6 mph, gusting to 25 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.
Sunday night	Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Patchy light fog after midnight. A chance of rain. Scattered thunderstorms likely. Low 63°. Wind east-southeast around 4 mph, gusting to 19 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Monday	Partly cloudy in the morning, becoming partly to mostly 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. Thunderstorms very likely, some possibly severe. High 84°. UV index up to 6. Wind southeast around 3 mph, gusting to 23 mph, in the morning, becoming northeast in the afternoon. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch.
Monday night	Fair in the evening, becoming partly cloudy after midnight. Light to moderate fog after midnight. Low 63°. Wind north-northeast around 4 mph, gusting to 18 mph.
Tuesday	Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Patchy light fog in the morning. High 82°. UV index up to 7. Wind east-northeast around 8 mph, gusting to 26 mph.
Tuesday night	Mostly clear in the evening, becoming fair after midnight. Relatively cool. Low 58°. Wind east around 7 mph, gusting to 23 mph, in the evening, becoming 4 mph after midnight.
Wednesday	Sunny. High 83°. UV index up to 9. Wind east around 5 mph, gusting to 25 mph.
Wednesday night	Fair in the evening, becoming partly cloudy after midnight. Relatively cool. Low 58°. Wind east around 4 mph, gusting to 21 mph, in the evening, becoming southeast after midnight.
Thursday	Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Hot. High 86°. UV index up to 8. Wind south around 6 mph, gusting to 25 mph.
Thursday night	Fair to partly cloudy in the evening, becoming partly cloudy after midnight. Low 60°. Wind south around 5 mph, gusting to 20 mph.
Friday	Partly to mostly cloudy in the morning, becoming mostly cloudy in the afternoon. Hot. High 89°. UV index up to 8. Wind southwest around 7 mph, gusting to 26 mph.
Friday night	Fair in the evening, becoming fair to partly cloudy after midnight. Patchy light fog after midnight. Low 62°. Wind south-southeast around 5 mph, gusting to 17 mph, in the evening, becoming south-southwest after midnight.

WXSIM forecast formatting script by Saratoga-Weather.org.

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