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: Monday, 01-Jun-2026 04:00 pm

Tonight Fair	Tuesday Mostly Sunny	Tuesday night Clear	Wednesday Mostly Sunny	Wednesday night Clear	Thursday Partly Cloudy	Thursday night Partly Cloudy	Friday Thunder storm
							<.1 in.
Low: 69°	High: 83°	Low: 61°	High: 83°	Low: 60°	High: 86°	Low: 62°	High: 87°

NE 4-24 mph	ENE 6-27→10-27 mph	ENE 5-25 mph	E 5-25 mph	ESE→S 4-23 mph	S 6-25 mph	S 6-21 mph	S 7-26 mph
	UV: 8 Very High		UV: 9 Very High		UV: 7 High		UV: 7 High

Tonight	Fair. Low 69°. Wind northeast around 4 mph, gusting to 24 mph.
Tuesday	Mostly sunny. High 83°. UV index up to 8. Wind east-northeast around 6 mph, gusting to 27 mph, in the morning, becoming 10 mph, gusting to 27 mph, in the afternoon.
Tuesday night	Clear. Low 61°. Wind east-northeast around 5 mph, gusting to 25 mph.
Wednesday	Partly to mostly sunny in the morning, becoming sunny in the afternoon. High 83°. UV index up to 9. Wind east around 5 mph, gusting to 25 mph.
Wednesday night	Clear in the evening, becoming fair after midnight. Relatively cool. Low 60°. Wind east-southeast around 4 mph, gusting to 23 mph, in the evening, becoming south after midnight.
Thursday	Partly cloudy. Hot. High 86°. UV index up to 7. Wind south around 6 mph, gusting to 25 mph.
Thursday night	Fair in the evening, becoming partly cloudy after midnight. Low 62°. Wind south around 6 mph, gusting to 21 mph.
Friday	Partly cloudy in the morning, becoming mostly cloudy in the afternoon. A slight chance of rain in the afternoon. Scattered thundershowers possible. Hot. High 87°. UV index up to 7. Wind south around 7 mph, gusting to 26 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.
Friday night	Mostly cloudy to cloudy. Light to moderate fog after midnight. A slight chance of rain in the evening, then rain likely after midnight. Precipitation showery or intermittent. Low 65°. Wind south around 6 mph, gusting to 17 mph. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Saturday	Mostly cloudy to cloudy in the morning, becoming partly 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 85°. UV index up to 10. Wind south-southwest around 8 mph, gusting to 24 mph. Chance of precipitation 70 percent. Precipitation mostly between a quarter and half an inch.
Saturday night	Partly to mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Moderate fog. Rain likely. Scattered thundershowers possible. Low 69°. Wind south around 5 mph, gusting to 17 mph. Chance of precipitation 70 percent. Precipitation mostly around a quarter of an inch.
Sunday	Mostly cloudy in the morning, becoming cloudy in the afternoon. Moderate fog in the morning. A chance of rain. Thunderstorms very likely, some possibly severe. High 81°. UV index up to 5. Wind west-southwest around 5 mph, gusting to 16 mph. Chance of precipitation 50 percent. Precipitation mostly less than a tenth of an inch.
Sunday night	Partly to mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Patchy light fog. A chance of rain in the evening, then a slight chance of rain after midnight. Thunderstorms very likely, some possibly severe. Low 71°. Wind south-southeast around 3 mph in the evening, becoming southwest after midnight. Chance of precipitation 50 percent. Precipitation mostly less than a tenth of an inch.

WXSIM forecast formatting script by Saratoga-Weather.org.

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