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, 24-Aug-2026 04:00 pm

Tonight Fog late	Tuesday Chance rain	Tuesday night Chance rain	Wednesday Fog a.m.	Wednesday night Fog late	Thursday Fog a.m.	Thursday night Fog late	Friday Fog a.m.
<.1 in.	<.1 in.	.1 in.	<.1 in.
Low: 62°	High: 82°	Low: 66°	High: 85°	Low: 65°	High: 85°	Low: 62°	High: 84°

ENE 3-19 mph	E 4-19 mph	E→SSE 4 mph	SSW→W 5-18 mph	NNW 4 mph	NW 5-23 mph	N 4-17 mph	N 3-21 mph
	UV: 6 High		UV: 7 High		UV: 7 High		UV: 7 High

Tonight	Fair to partly cloudy. Light to moderate fog after midnight. A chance of rain. Low 62°. Wind east-northeast around 3 mph, gusting to 19 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Tuesday	Partly to mostly sunny in the morning, becoming mostly cloudy in the afternoon. Light to moderate fog in the morning. A slight chance of rain in the morning, then a chance of rain in the afternoon. Precipitation showery or intermittent. High 82°. UV index up to 6. Wind east around 4 mph, gusting to 19 mph. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch.
Tuesday night	Mostly cloudy in the evening, becoming partly cloudy after midnight. Moderate fog after midnight. A chance of rain. Low 66°. Wind east around 4 mph in the evening, becoming south-southeast after midnight. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch.
Wednesday	Partly cloudy in the morning, becoming mostly sunny in the afternoon. Moderate fog in the morning. A chance of rain. High 85°. UV index up to 7. Wind south-southwest around 5 mph, gusting to 18 mph, in the morning, becoming west in the afternoon. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Wednesday night	Fair in the evening, becoming mostly clear after midnight. Patchy light fog after midnight. Low 65°. Wind north-northwest around 4 mph.
Thursday	Partly to mostly sunny. Patchy light fog in the morning. High 85°. UV index up to 7. Wind northwest around 5 mph, gusting to 23 mph.
Thursday night	Fair to partly cloudy in the evening, becoming clear after midnight. Patchy light fog after midnight. Low 62°. Wind north around 4 mph, gusting to 17 mph.
Friday	Sunny. Patchy light fog in the morning. High 84°. UV index up to 7. Wind north around 3 mph, gusting to 21 mph.
Friday night	Fair to partly cloudy in the evening, becoming mostly clear after midnight. Relatively cool. Low 61°. Wind east around 3 mph.
Saturday	Partly to mostly sunny in the morning, becoming partly cloudy in the afternoon. Hot. High 89°. UV index up to 7. Wind south-southeast around 4 mph, gusting to 22 mph.
Saturday night	Fair to partly cloudy in the evening, becoming fair after midnight. Low 64°. Wind south-southeast around 4 mph.
Sunday	Partly cloudy in the morning, becoming sunny in the afternoon. Very hot. High 94°. Heat index up to 98°. UV index up to 8. Wind south around 9 mph, gusting to 22 mph, in the morning, becoming 12 mph, gusting to 24 mph, in the afternoon.
Sunday night	Mostly clear in the evening, becoming mostly cloudy to cloudy after midnight. Low 73°. Wind south-southwest around 10 mph, gusting to 19 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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