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: Tuesday, 22-Sep-2026 04:00 pm

Tonight Fog late	Wednesday Fog a.m.	Wednesday night Fog late	Thursday Mostly Cloudy	Thursday night Partly Cloudy	Friday Partly Cloudy	Friday night Mostly Cloudy	Saturday Mostly Cloudy

Low: 54°	High: 72°	Low: 52°	High: 74°	Low: 55°	High: 75°	Low: 57°	High: 74°

NNE 6-17 mph	NNE 6-24 mph	NNE 4-20 mph	NNE 4-22 mph	NE 3-17 mph	ENE 4-20 mph	ENE 5-15 mph	ESE 5-22 mph
	UV: 5 Medium		UV: 6 High		UV: 4 Medium		UV: 5 Medium

Tonight	Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Patchy light fog in the evening, then light to moderate fog after midnight. Low 54°. Wind north-northeast around 6 mph, gusting to 17 mph.
Wednesday	Mostly sunny in the morning, becoming partly to mostly cloudy in the afternoon. Light to moderate fog in the morning. High 72°. UV index up to 5. Wind north-northeast around 6 mph, gusting to 24 mph.
Wednesday night	Fair to partly cloudy. Patchy light fog after midnight. Low 52°. Wind north-northeast around 4 mph, gusting to 20 mph.
Thursday	Mostly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. High 74°. UV index up to 6. Wind north-northeast around 4 mph, gusting to 22 mph.
Thursday night	Mostly cloudy in the evening, becoming partly cloudy after midnight. Low 55°. Wind northeast around 3 mph, gusting to 17 mph.
Friday	Partly cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. High 75°. UV index up to 4. Wind east-northeast around 4 mph, gusting to 20 mph.
Friday night	Mostly cloudy to cloudy in the evening, becoming mostly cloudy after midnight. Low 57°. Wind east-northeast around 5 mph, gusting to 15 mph.
Saturday	Cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. High 74°. UV index up to 5. Wind east-southeast around 5 mph, gusting to 22 mph.
Saturday night	Partly to mostly cloudy in the evening, becoming mostly cloudy after midnight. Patchy light fog after midnight. A slight chance of rain in the evening, then a chance of rain after midnight. Low 57°. Wind east-southeast around 5 mph, gusting to 19 mph. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch.
Sunday	Mostly 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. High 76°. UV index up to 4. Wind east-southeast around 4 mph, gusting to 18 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Sunday night	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Patchy light fog after midnight. A slight chance of rain. Low 57°. Wind east around 4 mph, gusting to 15 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.
Monday	Partly to mostly sunny in the morning, becoming sunny in the afternoon. Patchy light fog in the morning. Warm. High 79°. UV index up to 5. Wind east around 5 mph, gusting to 23 mph.
Monday night	Mostly clear in the evening, becoming partly to mostly cloudy after midnight. Low 57°. Wind east around 4 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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