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 05:00 am

Today Partly Cloudy	Tonight Partly Cloudy	Wednesday Mostly Cloudy	Wednesday night Mostly Cloudy	Thursday Thunder storm	Thursday night Thunder storm	Friday Rain likely	Friday night Partly Cloudy
				<.1 in.	.75 in.	.25 in.
High: 79°	Low: 57°	High: 87°	Low: 67°	High: 86°	Low: 64°	High: 71°	Low: 52°

SSE 3-17→7-21 mph	SSE 5 mph	S 7-21 mph	SSE 6-15 mph	S→SW 7-24 mph	NNE 4 mph	N 9-25 mph	NE 6-22 mph
UV: 6 High		UV: 5 Medium		UV: 4 Medium

Today	Sunny in the morning, becoming partly cloudy in the afternoon. Warm. High 79°. UV index up to 6. Wind south-southeast around 3 mph, gusting to 17 mph, in the morning, becoming 7 mph, gusting to 21 mph, in the afternoon.
Tonight	Partly cloudy in the evening, becoming mostly cloudy after midnight. Low 57°. Wind south-southeast around 5 mph.
Wednesday	Mostly cloudy to cloudy in the morning, becoming mostly cloudy in the afternoon. Unusually hot. High 87°. UV index up to 5. Wind south around 7 mph, gusting to 21 mph.
Wednesday night	Partly to mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Warm. Low 67°. Wind south-southeast around 6 mph, gusting to 15 mph.
Thursday	Mostly cloudy in the morning, becoming cloudy in the afternoon. A chance of rain. Scattered thundershowers possible. Unusually hot. High 86°. UV index up to 4. Wind south around 7 mph, gusting to 24 mph, in the morning, becoming southwest in the afternoon. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Thursday night	Cloudy. Patchy light fog in the evening, then light to moderate fog after midnight. A chance of rain in the evening, then rain likely after midnight. Scattered thundershowers possible. Low 64°. Wind north-northeast around 4 mph. Chance of precipitation 80 percent. Precipitation mostly between half an inch and one inch.
Friday	Dense overcast in the morning, becoming partly to mostly cloudy in the afternoon. Light to moderate fog in the morning. Rain likely in the morning, then a slight chance of rain in the afternoon. Precipitation showery or intermittent. High 71°. Wind north around 9 mph, gusting to 25 mph. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Friday night	Clear in the evening, becoming fair to partly cloudy after midnight. Low 52°. Wind northeast around 6 mph, gusting to 22 mph.
Saturday	Partly cloudy. Patchy light fog in the morning. High 73°. UV index up to 5. Wind northeast around 6 mph, gusting to 24 mph.
Saturday night	Fair to partly cloudy. Low 49°. Wind northeast around 3 mph, gusting to 17 mph.
Sunday	Sunny. Patchy light fog in the morning. High 74°. UV index up to 6. Wind north-northeast around 4 mph, gusting to 21 mph.
Sunday night	Clear. Patchy light fog after midnight. Low 48°. Wind north around 5 mph.
Monday	Sunny. Patchy light fog in the morning. High 69°. UV index up to 5. Wind north-northeast around 7 mph, gusting to 24 mph.
Monday night	Clear. Cool. Low 47°. Wind east-northeast around 5 mph, gusting to 18 mph.

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