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: Monday, 28-Sep-2026 04:00 pm

Tonight Clear	Tuesday Partly Cloudy	Tuesday night Partly Cloudy	Wednesday Mostly Cloudy	Wednesday night Partly Cloudy	Thursday Thunder storm	Thursday night Thunder storm	Friday Thunder storm
					<.1 in.	<.25 in.	.25 in.
Low: 52°	High: 82°	Low: 59°	High: 86°	Low: 64°	High: 85°	Low: 67°	High: 69°

E 2-19 mph	SE 5-23 mph	SE 5-16 mph	SSE 7-20 mph	SSW 7-16 mph	SSW 7-23 mph	NNE 3 mph	N 6-20→9-25 mph
	UV: 5 Medium		UV: 5 Medium		UV: 5 Medium

Tonight	Clear. Low 52°. Wind east around 2 mph, gusting to 19 mph.
Tuesday	Sunny in the morning, becoming partly cloudy in the afternoon. Warm. High 82°. UV index up to 5. Wind southeast around 5 mph, gusting to 23 mph.
Tuesday night	Partly cloudy in the evening, becoming mostly cloudy after midnight. Low 59°. Wind southeast around 5 mph, gusting to 16 mph.
Wednesday	Mostly cloudy to cloudy in the morning, becoming partly to mostly cloudy in the afternoon. Unusually hot. High 86°. UV index up to 5. Wind south-southeast around 7 mph, gusting to 20 mph.
Wednesday night	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Low 64°. Wind south-southwest around 7 mph, gusting to 16 mph.
Thursday	Partly to mostly cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. A chance of rain. Scattered thundershowers possible. Unusually hot. High 85°. UV index up to 5. Wind south-southwest around 7 mph, gusting to 23 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Thursday night	Cloudy in the evening, becoming dense overcast after midnight. Rain likely. Scattered thundershowers possible. Warm. Low 67°. Wind north-northeast around 3 mph. Chance of precipitation 60 percent. Precipitation mostly less than a quarter of an inch.
Friday	Dense overcast in the morning, becoming 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. Scattered thundershowers possible. High 69°. Wind north around 6 mph, gusting to 20 mph, in the morning, becoming 9 mph, gusting to 25 mph, in the afternoon. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Friday night	Partly cloudy in the evening, becoming mostly clear after midnight. Patchy light fog after midnight. Low 53°. Wind north-northeast around 7 mph, gusting to 25 mph.
Saturday	Mostly sunny in the morning, becoming sunny in the afternoon. Light to moderate fog in the morning. High 74°. UV index up to 6. Wind northeast around 6 mph, gusting to 24 mph.
Saturday night	Clear in the evening, becoming partly cloudy after midnight. Patchy light fog after midnight. Low 50°. Wind northeast around 3 mph, gusting to 17 mph.
Sunday	Sunny. Patchy light fog in the morning. High 74°. UV index up to 5. Wind north around 5 mph, gusting to 20 mph, in the morning, becoming 9 mph, gusting to 23 mph, in the afternoon.
Sunday night	Clear. Patchy light fog after midnight. Low 50°. Wind north around 6 mph, gusting to 19 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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