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: Thursday, 26-Mar-2026 04:00 pm

Tonight Thunder storm	Friday Mostly Cloudy	Friday night Clear	Saturday Sunny	Saturday night Partly Cloudy	Sunday Partly Cloudy	Sunday night Partly Cloudy	Monday Partly Cloudy
.1 in.
Low: 50°	High: 59°	Low: 36°	High: 62°	Low: 40°	High: 73°	Low: 46°	High: 84°

NNW 9-25→13-30 mph	N 12-31 mph	N 8-28→5-17 mph	E→SSE 6-26 mph	SSE 8-24 mph	SSE 9-27 mph	S 8-21 mph	SSW 10-28 mph
	UV: 7 High		UV: 7 High		UV: 6 High		UV: 6 High

Tonight	Partly to mostly cloudy in the evening, becoming cloudy after midnight. A chance of rain. Thunderstorms very likely, some possibly severe. Low 50°. Wind north-northwest around 9 mph, gusting to 25 mph, in the evening, becoming 13 mph, gusting to 30 mph, after midnight. Chance of precipitation 50 percent. Precipitation mostly around a tenth of an inch.
Friday	Partly to mostly cloudy in the morning, becoming sunny in the afternoon. Breezy. High 59°. UV index up to 7. Wind north around 12 mph, gusting to 31 mph.
Friday night	Fair in the evening, becoming clear after midnight. Low 36°. Wind north around 8 mph, gusting to 28 mph, in the evening, becoming 5 mph, gusting to 17 mph, after midnight.
Saturday	Sunny. High 62°. UV index up to 7. Wind east around 6 mph, gusting to 26 mph, in the morning, becoming south-southeast in the afternoon.
Saturday night	Partly cloudy in the evening, becoming partly to mostly cloudy after midnight. Low 40°. Wind south-southeast around 8 mph, gusting to 24 mph.
Sunday	Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Warm. High 73°. UV index up to 6. Wind south-southeast around 9 mph, gusting to 27 mph.
Sunday night	Partly cloudy in the evening, becoming partly to mostly cloudy after midnight. Low 46°. Wind south around 8 mph, gusting to 21 mph.
Monday	Partly to mostly sunny in the morning, becoming partly cloudy in the afternoon. Unusually hot. High 84°. UV index up to 6. Wind south-southwest around 10 mph, gusting to 28 mph.
Monday night	Partly cloudy in the evening, becoming partly to mostly cloudy after midnight. Mild. Low 58°. Wind south-southwest around 10 mph, gusting to 22 mph.
Tuesday	Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Breezy with near record warmth. High 89°. UV index up to 6. Wind south-southwest around 13 mph, gusting to 32 mph.
Tuesday night	Partly cloudy in the evening, becoming cloudy after midnight. Patchy light fog in the evening, then light to moderate fog after midnight. A chance of rain in the evening, then rain likely after midnight. Scattered thundershowers possible. Low 54°. Wind south-southwest around 10 mph, gusting to 26 mph, in the evening, becoming north-northwest after midnight. Chance of precipitation 80 percent. Precipitation mostly between half an inch and one inch.
Wednesday	Mostly cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. A chance of rain. Scattered thunderstorms likely. Breezy and unusually warm. High 77°. Wind south-southwest around 13 mph, gusting to 27 mph, in the morning, becoming 18 mph, gusting to 27 mph, in the afternoon. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Wednesday night	Mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. A chance of rain after midnight. Thunderstorms very likely, some possibly severe. Windy and unusually warm. Low 65°. Wind south-southwest around 17 mph, gusting to 27 mph. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch.

WXSIM forecast formatting script by Saratoga-Weather.org.

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