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: Wednesday, 17-Jun-2026 05:00 am

Today Thunder storm	Tonight Thunder storm	Thursday Fog a.m.	Thursday night Fog late	Friday Fog a.m.	Friday night Fog late	Saturday Fog a.m.	Saturday night Thunder storm
<.25 in.	<.25 in.						.25 in.
High: 85°	Low: 65°	High: 84°	Low: 63°	High: 84°	Low: 64°	High: 89°	Low: 68°

SSW 8-26→17-30 mph	W 13-24→8-16 mph	WNW 6-25 mph	WNW 3-22 mph	NW→NNE 3-21 mph	ESE→S 4-17 mph	SSW→ESE 4-22 mph	SE 4-16 mph
UV: 8 Very High		UV: 8 Very High		UV: 9 Very High		UV: 9 Very High

Today	Partly cloudy. A chance of rain. Scattered thundershowers possible. Breezy. High 85°. UV index up to 8. Wind south-southwest around 8 mph, gusting to 26 mph, in the morning, becoming 17 mph, gusting to 30 mph, in the afternoon. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Tonight	Partly cloudy in the evening, becoming fair after midnight. Light to moderate fog in the evening, then moderate to dense fog after midnight. A chance of rain. Scattered thunderstorms likely. Low 65°. Wind west around 13 mph, gusting to 24 mph, in the evening, becoming 8 mph, gusting to 16 mph, after midnight. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Thursday	Partly to mostly cloudy. Light to moderate fog in the morning. High 84°. UV index up to 8. Wind west-northwest around 6 mph, gusting to 25 mph.
Thursday night	Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Patchy light fog after midnight. Relatively cool. Low 63°. Wind west-northwest around 3 mph, gusting to 22 mph.
Friday	Partly cloudy. Patchy light fog in the morning. High 84°. UV index up to 9. Wind northwest around 3 mph, gusting to 21 mph, in the morning, becoming north-northeast in the afternoon.
Friday night	Fair to partly cloudy in the evening, becoming partly cloudy after midnight. Patchy light fog after midnight. Relatively cool. Low 64°. Wind east-southeast around 4 mph, gusting to 17 mph, in the evening, becoming south after midnight.
Saturday	Partly to mostly sunny in the morning, becoming partly cloudy in the afternoon. Patchy light fog in the morning. Hot. High 89°. UV index up to 9. Wind south-southwest around 4 mph, gusting to 22 mph, in the morning, becoming east-southeast in the afternoon.
Saturday night	Partly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Light to moderate fog after midnight. A slight chance of rain in the evening, then a chance of rain after midnight. Scattered thundershowers possible. Low 68°. Wind southeast around 4 mph, gusting to 16 mph. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Sunday	Cloudy in the morning, becoming mostly cloudy in the afternoon. Light to moderate fog in the morning, then patchy light fog in the afternoon. Rain very likely. Scattered thundershowers possible. High 83°. UV index up to 7. Wind south-southwest around 9 mph, gusting to 25 mph. Chance of precipitation 80 percent. Precipitation mostly around half an inch.
Sunday night	Fair to partly cloudy in the evening, becoming partly cloudy after midnight. Moderate 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 west-southwest around 7 mph, gusting to 20 mph. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Monday	Mostly cloudy to cloudy in the morning, becoming partly to mostly cloudy in the afternoon. Patchy light fog in the morning. A chance of rain. High 80°. UV index up to 9. Wind north around 8 mph, gusting to 27 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Monday night	Partly cloudy in the evening, becoming fair after midnight. Patchy light fog after midnight. Relatively cool. Low 62°. Wind northeast around 4 mph, gusting to 23 mph, in the evening, becoming east-southeast after midnight.
Tuesday	Partly to mostly cloudy in the morning, becoming cloudy in the afternoon. High 79°. UV index up to 7. Wind southeast around 5 mph, gusting to 24 mph.
Tuesday night	Cloudy. A slight chance of rain. Low 67°. Wind east-northeast around 3 mph, gusting to 21 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.

WXSIM forecast formatting script by Saratoga-Weather.org.

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