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, 14-Jun-2026 04:00 pm

Tonight Partly Cloudy	Monday Partly Cloudy	Monday night Fair	Tuesday Thunder storm	Tuesday night Fog late	Wednesday Fog a.m.	Wednesday night Thunder storm	Thursday Fog a.m.
			.25 in.			.25 in.	<.1 in.
Low: 58°	High: 80°	Low: 58°	High: 82°	Low: 61°	High: 88°	Low: 68°	High: 83°
					Heat: 92°
NNW 4-25 mph	NW 4-23 mph	SW 4-19 mph	SW 9-29 mph	W→SSE 5-18 mph	S 8-24→14-30 mph	WSW 12-28 mph	WNW 8-27 mph
	UV: 7 High		UV: 6 High		UV: 9 Very High		UV: 9 Very High

Tonight	Fair in the evening, becoming partly cloudy after midnight. Relatively cool. Low 58°. Wind north-northwest around 4 mph, gusting to 25 mph.
Monday	Mostly sunny in the morning, becoming partly cloudy in the afternoon. High 80°. UV index up to 7. Wind northwest around 4 mph, gusting to 23 mph.
Monday night	Fair. Unusually cool. Low 58°. Wind southwest around 4 mph, gusting to 19 mph.
Tuesday	Partly to mostly cloudy. A slight chance of rain in the morning, then a chance of rain in the afternoon. Scattered thundershowers possible. High 82°. UV index up to 6. Wind southwest around 9 mph, gusting to 29 mph. Chance of precipitation 50 percent. Precipitation mostly around a quarter of an inch.
Tuesday night	Fair to partly cloudy in the evening, becoming mostly clear after midnight. Patchy light fog after midnight. Relatively cool. Low 61°. Wind west around 5 mph, gusting to 18 mph, in the evening, becoming south-southeast after midnight.
Wednesday	Mostly sunny in the morning, becoming partly cloudy in the afternoon. Patchy light fog in the morning. Hot. High 88°. Heat index up to 92°. UV index up to 9. Wind south around 8 mph, gusting to 24 mph, in the morning, becoming 14 mph, gusting to 30 mph, in the afternoon.
Wednesday night	Partly cloudy. 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. Thunderstorms very likely, some possibly severe. Breezy. Low 68°. Wind west-southwest around 12 mph, gusting to 28 mph. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Thursday	Partly cloudy. Patchy light fog in the morning. A chance of rain. High 83°. UV index up to 9. Wind west-northwest around 8 mph, gusting to 27 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Thursday night	Mostly clear in the evening, becoming clear after midnight. Light to moderate fog after midnight. Relatively cool. Low 62°. Wind north-northeast around 4 mph, gusting to 23 mph, in the evening, becoming northwest after midnight.
Friday	Sunny in the morning, becoming partly to mostly sunny in the afternoon. Light to moderate fog in the morning. High 81°. UV index up to 9. Wind northwest around 5 mph, gusting to 24 mph.
Friday night	Clear in the evening, becoming fair to partly cloudy after midnight. Patchy light fog after midnight. Relatively cool. Low 62°. Wind east around 3 mph, gusting to 19 mph, in the evening, becoming south-southwest after midnight.
Saturday	Mostly sunny in the morning, becoming sunny in the afternoon. Patchy light fog in the morning. High 87°. UV index up to 10. Wind south-southwest around 4 mph, gusting to 23 mph.
Saturday night	Fair to partly cloudy in the evening, becoming mostly cloudy after midnight. A chance of rain after midnight. Precipitation showery or intermittent. Low 64°. Wind south-southeast around 6 mph, gusting to 17 mph, in the evening, becoming 10 mph, gusting to 16 mph, after midnight. Chance of precipitation 40 percent. Precipitation mostly less than a quarter of an inch.

WXSIM forecast formatting script by Saratoga-Weather.org.

Powered by Davis Vantage Pro2 and CumulusMX v 4.6.4 (b4128) MXUI Template v 2.2.6 by Silver Acorn Valid HTML5