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, 20-Aug-2026 05:00 am

Today Chance rain	Tonight Fog	Friday Fog a.m.	Friday night Fog late	Saturday Fog a.m.	Saturday night Fog late	Sunday Fog a.m.	Sunday night Partly Cloudy
.1 in.	<.1 in.	<.1 in.
High: 83°	Low: 66°	High: 84°	Low: 67°	High: 85°	Low: 64°	High: 82°	Low: 62°

N 4-23 mph	NE 2-16 mph	SSE→SW 3-21 mph	SSW→W 3 mph	NW 5-23 mph	N 4-17 mph	N 4-22 mph	ENE→ESE 3-17 mph
UV: 5 Medium		UV: 7 High		UV: 7 High		UV: 6 High

Today	Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. A chance of rain. High 83°. UV index up to 5. Wind north around 4 mph, gusting to 23 mph. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch.
Tonight	Partly cloudy in the evening, becoming fair after midnight. Patchy light fog. A slight chance of rain. Low 66°. Wind northeast around 2 mph, gusting to 16 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.
Friday	Mostly sunny. Patchy light fog in the morning. A slight chance of rain. High 84°. UV index up to 7. Wind south-southeast around 3 mph, gusting to 21 mph, in the morning, becoming southwest in the afternoon. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.
Friday night	Fair. Patchy light fog after midnight. Low 67°. Wind south-southwest around 3 mph in the evening, becoming west after midnight.
Saturday	Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Patchy light fog in the morning. High 85°. UV index up to 7. Wind northwest around 5 mph, gusting to 23 mph.
Saturday night	Clear. Patchy light fog after midnight. Low 64°. Wind north around 4 mph, gusting to 17 mph.
Sunday	Mostly sunny in the morning, becoming partly cloudy in the afternoon. Patchy light fog in the morning. High 82°. UV index up to 6. Wind north around 4 mph, gusting to 22 mph.
Sunday night	Partly cloudy in the evening, becoming fair after midnight. Relatively cool. Low 62°. Wind east-northeast around 3 mph, gusting to 17 mph, in the evening, becoming east-southeast after midnight.
Monday	Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. A chance of rain. High 82°. UV index up to 6. Wind east-southeast around 4 mph, gusting to 22 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Monday night	Fair in the evening, becoming fair to partly cloudy after midnight. Light to moderate fog after midnight. A chance of rain after midnight. Relatively cool. Low 62°. Wind east-southeast around 5 mph, gusting to 18 mph. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch.
Tuesday	Mostly cloudy to cloudy in the morning, becoming mostly cloudy in the afternoon. Light to moderate fog in the morning. A chance of rain in the morning, then a slight chance of rain in the afternoon. Precipitation showery or intermittent. High 81°. UV index up to 5. Wind southeast around 6 mph, gusting to 19 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Tuesday night	Fair in the evening, becoming partly to mostly cloudy after midnight. Low 66°. Wind east around 4 mph, gusting to 16 mph.
Wednesday	Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Patchy light fog in the morning. High 86°. UV index up to 7. Wind east-northeast around 3 mph, gusting to 16 mph, in the morning, becoming north-northeast in the afternoon.
Wednesday night	Fair to partly cloudy in the evening, becoming clear after midnight. Patchy light fog after midnight. Low 68°. Wind east-northeast around 3 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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