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, 23-Aug-2026 04:00 pm

Tonight Fog late	Monday Fog a.m.	Monday night Fog late	Tuesday Fog a.m.	Tuesday night Partly Cloudy	Wednesday Partly Cloudy	Wednesday night Clear	Thursday Fog a.m.
	<.1 in.	<.1 in.	<.1 in.
Low: 62°	High: 83°	Low: 64°	High: 84°	Low: 66°	High: 88°	Low: 65°	High: 86°

NNE 3-20 mph	ESE 2-20 mph	E 3-15 mph	ESE 4-19 mph	SE 3-15 mph	WSW 4-20 mph	NW 3 mph	NNW 4-20 mph
	UV: 7 High		UV: 6 High		UV: 7 High		UV: 7 High

Tonight	Fair to partly cloudy in the evening, becoming fair after midnight. Patchy light fog after midnight. Relatively cool. Low 62°. Wind north-northeast around 3 mph, gusting to 20 mph.
Monday	Mostly sunny in the morning, becoming partly cloudy in the afternoon. Patchy light fog in the morning. A chance of rain. High 83°. UV index up to 7. Wind east-southeast around 2 mph, gusting to 20 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Monday night	Fair to partly cloudy in the evening, becoming fair after midnight. Patchy light fog in the evening, then moderate fog after midnight. A chance of rain. Low 64°. Wind east around 3 mph, gusting to 15 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Tuesday	Partly to mostly sunny in the morning, becoming partly to mostly cloudy in the afternoon. Light to moderate fog in the morning. A chance of rain. High 84°. UV index up to 6. Wind east-southeast around 4 mph, gusting to 19 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Tuesday night	Partly cloudy in the evening, becoming partly to mostly cloudy after midnight. Low 66°. Wind southeast around 3 mph, gusting to 15 mph.
Wednesday	Partly cloudy in the morning, becoming mostly sunny in the afternoon. Hot. High 88°. UV index up to 7. Wind west-southwest around 4 mph, gusting to 20 mph.
Wednesday night	Clear in the evening, becoming fair after midnight. Low 65°. Wind northwest around 3 mph.
Thursday	Sunny in the morning, becoming mostly sunny in the afternoon. Patchy light fog in the morning. High 86°. UV index up to 7. Wind north-northwest around 4 mph, gusting to 20 mph.
Thursday night	Fair in the evening, becoming clear after midnight. Low 63°. Wind northeast around 2 mph.
Friday	Partly cloudy in the morning, becoming sunny in the afternoon. Hot. High 86°. UV index up to 7. Wind east around 2 mph, gusting to 18 mph.
Friday night	Fair in the evening, becoming fair to partly cloudy after midnight. Low 64°. Wind east around 4 mph in the evening, becoming southeast after midnight.
Saturday	Mostly cloudy to cloudy in the morning, becoming partly to mostly cloudy in the afternoon. Patchy light 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 82°. UV index up to 7. Wind south-southeast around 5 mph, gusting to 15 mph, in the morning, becoming 9 mph, gusting to 22 mph, in the afternoon. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Saturday night	Cloudy. Light to moderate fog. Rain likely. Precipitation showery or intermittent. Low 70°. Wind south-southeast around 4 mph, gusting to 19 mph. Chance of precipitation 80 percent. Precipitation mostly between 1 and 2 inches.

WXSIM forecast formatting script by Saratoga-Weather.org.

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