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, 29-Sep-2026 04:00 pm

Tonight Mostly Cloudy	Wednesday Mostly Cloudy	Wednesday night Mostly Cloudy	Thursday Rain likely	Thursday night Rain likely	Friday Rain likely	Friday night Fog late	Saturday Fog a.m.
			1.0 in.	2.0 in.	.75 in.
Low: 62°	High: 89°	Low: 67°	High: 85°	Low: 64°	High: 71°	Low: 54°	High: 72°

SSE 5-20 mph	S 7-24 mph	SSE 6-16 mph	SSE→WSW 6-22 mph	WNW→N 2→6-19 mph	NNE 9-25 mph	NNE 6-21 mph	NE 5-21 mph
	UV: 6 High		UV: 4 Medium		UV: 6 High		UV: 6 High

Tonight	Partly to mostly cloudy in the evening, becoming mostly cloudy after midnight. Low 62°. Wind south-southeast around 5 mph, gusting to 20 mph.
Wednesday	Partly to mostly cloudy. Unusually hot. High 89°. UV index up to 6. Wind south around 7 mph, gusting to 24 mph.
Wednesday night	Mostly cloudy to cloudy. Warm. Low 67°. Wind south-southeast around 6 mph, gusting to 16 mph.
Thursday	Mostly cloudy to cloudy in the morning, becoming cloudy in the afternoon. Light to moderate fog in the afternoon. A slight chance of rain in the morning, then rain likely in the afternoon. Precipitation showery or intermittent. Unusually hot. High 85°. UV index up to 4. Wind south-southeast around 6 mph, gusting to 22 mph, in the morning, becoming west-southwest in the afternoon. Chance of precipitation 70 percent. Precipitation mostly around an inch.
Thursday night	Dense overcast. Light to moderate fog. Rain likely. Precipitation showery or intermittent. Mild. Low 64°. Wind west-northwest around 2 mph in the evening, becoming north around 6 mph, gusting to 19 mph, after midnight. Chance of precipitation 80 percent. Precipitation mostly around 2 inches.
Friday	Mostly cloudy in the morning, becoming mostly sunny in the afternoon. Light to moderate fog in the morning. Rain likely. High 71°. UV index up to 6. Wind north-northeast around 9 mph, gusting to 25 mph. Chance of precipitation 70 percent. Precipitation mostly between half an inch and one inch.
Friday night	Clear. Patchy light fog in the evening, then moderate fog after midnight. Low 54°. Wind north-northeast around 6 mph, gusting to 21 mph.
Saturday	Sunny. Moderate fog in the morning. High 72°. UV index up to 6. Wind northeast around 5 mph, gusting to 21 mph.
Saturday night	Clear. Patchy light fog in the evening, then light to moderate fog after midnight. Low 52°. Wind east-northeast around 2 mph in the evening, becoming north after midnight.
Sunday	Sunny. Light to moderate fog in the morning. High 72°. UV index up to 6. Wind north-northwest around 4 mph, gusting to 20 mph.
Sunday night	Clear. Patchy light fog in the evening, then moderate fog after midnight. Low 53°. Wind north-northwest around 6 mph, gusting to 16 mph.
Monday	Sunny. Light to moderate fog in the morning. High 67°. UV index up to 5. Wind northeast around 7 mph, gusting to 25 mph.
Monday night	Clear. Patchy light fog after midnight. Low 49°. Wind east-northeast around 5 mph, gusting to 18 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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