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: Sunday, 10-May-2026 04:00 pm

Tonight Partly Cloudy	Monday Sunny	Monday night Mostly Clear	Tuesday Mostly Sunny	Tuesday night Chance rain	Wednesday Fog a.m.	Wednesday night Clear	Thursday Sunny
				.25 in.
Low: 48°	High: 75°	Low: 49°	High: 80°	Low: 55°	High: 75°	Low: 50°	High: 77°

NNW→SSW 2-17 mph	W 5-23 mph	SW 4-19 mph	SW 9-28 mph	W 7-21 mph	WNW 9-27 mph	NNW→ENE 4-24 mph	SE 5-24 mph
	UV: 7 High		UV: 7 High		UV: 7 High		UV: 8 Very High

Tonight	Partly cloudy in the evening, becoming clear after midnight. Cool. Low 48°. Wind north-northwest around 2 mph, gusting to 17 mph, in the evening, becoming south-southwest after midnight.
Monday	Sunny. High 75°. UV index up to 7. Wind west around 5 mph, gusting to 23 mph.
Monday night	Mostly clear. Cool. Low 49°. Wind southwest around 4 mph, gusting to 19 mph.
Tuesday	Sunny in the morning, becoming mostly sunny in the afternoon. High 80°. UV index up to 7. Wind southwest around 9 mph, gusting to 28 mph.
Tuesday night	Partly cloudy in the evening, becoming mostly clear after midnight. Patchy light 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 55°. Wind west around 7 mph, gusting to 21 mph. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Wednesday	Sunny. Patchy light fog in the morning. High 75°. UV index up to 7. Wind west-northwest around 9 mph, gusting to 27 mph.
Wednesday night	Clear. Cool. Low 50°. Wind north-northwest around 4 mph, gusting to 24 mph, in the evening, becoming east-northeast after midnight.
Thursday	Sunny. High 77°. UV index up to 8. Wind southeast around 5 mph, gusting to 24 mph.
Thursday night	Partly cloudy in the evening, becoming mostly cloudy after midnight. A slight chance of rain after midnight. Cool. Low 52°. Wind southeast around 9 mph, gusting to 22 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.
Friday	Partly to mostly cloudy in the morning, becoming partly cloudy in the afternoon. A slight chance of rain. Scattered thundershowers possible. Breezy and hot. High 86°. UV index up to 7. Wind south around 14 mph, gusting to 32 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.
Friday night	Fair in the evening, becoming clear after midnight. Breezy. Low 60°. Wind south around 12 mph, gusting to 28 mph.
Saturday	Partly to mostly sunny in the morning, becoming cloudy in the afternoon. A slight chance of rain in the morning, then a chance of rain in the afternoon. Scattered thunderstorms likely, some possibly severe. Breezy and hot. High 87°. UV index up to 7. Wind south around 12 mph, gusting to 29 mph. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch.
Saturday night	Cloudy in the evening, becoming partly to mostly cloudy after midnight. Patchy light fog in the evening, then light to moderate fog after midnight. Rain very likely. Severe thunderstorms likely, with possible tornados. Breezy and warm. Low 69°. Wind south-southwest around 11 mph, gusting to 23 mph. Chance of precipitation 80 percent. Precipitation mostly around an inch.

WXSIM forecast formatting script by Saratoga-Weather.org.

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