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, 25-Mar-2026 04:00 pm

Tonight Fog late	Thursday Fog a.m.	Thursday night Thunder storm	Friday Mostly Cloudy	Friday night Clear	Saturday Mostly Sunny	Saturday night Partly Cloudy	Sunday Partly Cloudy
		.25 in.
Low: 57°	High: 89°	Low: 51°	High: 60°	Low: 37°	High: 61°	Low: 42°	High: 72°

SW 9-27 mph	SW 11-30 mph	SW→NNE 7-21→12-28 mph	NNE 12-31 mph	N 7-27 mph	E→SE 4-26→7-26 mph	SSE 7-23 mph	SSE 8-26 mph
	UV: 7 High		UV: 7 High		UV: 6 High		UV: 6 High

Tonight	Mostly clear in the evening, becoming partly cloudy after midnight. Patchy light fog after midnight. Mild. Low 57°. Wind southwest around 9 mph, gusting to 27 mph.
Thursday	Sunny in the morning, becoming mostly sunny in the afternoon. Patchy light fog in the morning. Breezy with near record warmth. High 89°. UV index up to 7. Wind southwest around 11 mph, gusting to 30 mph.
Thursday night	Partly cloudy in the evening, becoming cloudy after midnight. A slight chance of rain in the evening, then a chance of rain after midnight. Scattered thundershowers possible. Low 51°. Wind southwest around 7 mph, gusting to 21 mph, in the evening, becoming north-northeast around 12 mph, gusting to 28 mph, after midnight. Chance of precipitation 50 percent. Precipitation mostly around a quarter of an inch.
Friday	Partly to mostly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Breezy. High 60°. UV index up to 7. Wind north-northeast around 12 mph, gusting to 31 mph.
Friday night	Fair in the evening, becoming clear after midnight. Low 37°. Wind north around 7 mph, gusting to 27 mph.
Saturday	Sunny in the morning, becoming mostly sunny in the afternoon. High 61°. UV index up to 6. Wind east around 4 mph, gusting to 26 mph, in the morning, becoming southeast around 7 mph, gusting to 26 mph, in the afternoon.
Saturday night	Partly cloudy in the evening, becoming partly to mostly cloudy after midnight. Low 42°. Wind south-southeast around 7 mph, gusting to 23 mph.
Sunday	Partly to mostly cloudy in the morning, becoming partly cloudy in the afternoon. Mild. High 72°. UV index up to 6. Wind south-southeast around 8 mph, gusting to 26 mph.
Sunday night	Partly cloudy. Low 46°. Wind south around 10 mph, gusting to 22 mph.
Monday	Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. Unusually hot. High 83°. UV index up to 5. Wind south-southwest around 10 mph, gusting to 26 mph.
Monday night	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Mild. Low 58°. Wind south-southwest around 8 mph, gusting to 18 mph.
Tuesday	Mostly cloudy to cloudy in the morning, becoming cloudy in the afternoon. Unusually warm. High 77°. Wind south-southwest around 10 mph, gusting to 25 mph.
Tuesday night	Mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Breezy and mild. Low 62°. Wind south-southwest around 12 mph, gusting to 21 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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