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: Saturday, 19-Sep-2026 04:00 pm

Tonight Partly Cloudy	Sunday Partly Cloudy	Sunday night Mostly Cloudy	Monday Mostly Cloudy	Monday night Mostly Cloudy	Tuesday Cloudy	Tuesday night Mostly Cloudy	Wednesday Mostly Sunny
		<.1 in.	<.1 in.	<.1 in.	<.1 in.
Low: 72°	High: 90°	Low: 68°	High: 77°	Low: 61°	High: 70°	Low: 54°	High: 74°
	Heat: 94°
SSE→SW 3-20 mph	W 5-24 mph	N 6-20 mph	N 6-23 mph	N 7-22 mph	NNE 7-25 mph	NNE 6-22 mph	NNE 7-25 mph
	UV: 6 High		UV: 5 Medium				UV: 6 High

Tonight	Fair to partly cloudy in the evening, becoming partly cloudy after midnight. Warm. Low 72°. Wind south-southeast around 3 mph, gusting to 20 mph, in the evening, becoming southwest after midnight.
Sunday	Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. Unusually hot. High 90°. Heat index up to 94°. UV index up to 6. Wind west around 5 mph, gusting to 24 mph.
Sunday night	Partly to mostly cloudy in the evening, becoming dense overcast after midnight. A chance of rain. Warm. Low 68°. Wind north around 6 mph, gusting to 20 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Monday	Cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. A chance of rain. High 77°. UV index up to 5. Wind north around 6 mph, gusting to 23 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Monday night	Mostly cloudy to cloudy in the evening, becoming cloudy after midnight. A slight chance of rain. Low 61°. Wind north around 7 mph, gusting to 22 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.
Tuesday	Cloudy. A slight chance of rain. High 70°. Wind north-northeast around 7 mph, gusting to 25 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.
Tuesday night	Mostly cloudy in the evening, becoming partly to mostly cloudy after midnight. Low 54°. Wind north-northeast around 6 mph, gusting to 22 mph.
Wednesday	Sunny in the morning, becoming partly to mostly sunny in the afternoon. High 74°. UV index up to 6. Wind north-northeast around 7 mph, gusting to 25 mph.
Wednesday night	Fair to partly cloudy. Low 51°. Wind northeast around 5 mph, gusting to 22 mph.
Thursday	Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. High 75°. UV index up to 6. Wind northeast around 5 mph, gusting to 24 mph.
Thursday night	Mostly cloudy. Low 57°. Wind northeast around 5 mph, gusting to 19 mph.
Friday	Cloudy in the morning, becoming dense overcast in the afternoon. A chance of rain in the afternoon. High 70°. Wind east-northeast around 6 mph, gusting to 19 mph. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch.
Friday night	Dense overcast. A chance of rain in the evening, then a slight chance of rain after midnight. Low 58°. Wind east-northeast around 8 mph, gusting to 17 mph. Chance of precipitation 50 percent. Precipitation mostly around a tenth of an inch.

WXSIM forecast formatting script by Saratoga-Weather.org.

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