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, 16-Mar-2026 05:00 am

Today Freezing Rain	Tonight Partly Cloudy	Tuesday Mostly Cloudy	Tuesday night Mostly Cloudy	Wednesday Mostly Sunny	Wednesday night Partly Cloudy	Thursday Sunny	Thursday night Mostly Clear
<.1 in.
High: 23°	Low: 12°	High: 39°	Low: 33°	High: 64°	Low: 37°	High: 73°	Low: 37°
	WCh: 1°		WCh: 25°
WNW 17-31 mph	WNW 10-24 mph	WNW→SSW 5-23 mph	SE 6-23→10-22 mph	S→WSW 8-25 mph	NW→S 2-19 mph	SSW→WNW 3-22 mph	N→S calm
				UV: 4 Medium		UV: 5 Medium

Today	Dense overcast in the morning, becoming cloudy in the afternoon. A slight chance of a mix of snow, freezing rain, and sleet in the morning, then a slight chance of snow in the afternoon. Windy and extremely cold. High 23°, but temperatures falling in the afternoon. Wind chill around 8. Wind west-northwest around 17 mph, gusting to 31 mph. Chance of precipitation 30 percent. Precipitation (liquid equivalent) mostly less than a tenth of an inch. Little or no snow or ice (on ground) accumulation expected. Little if any freezing rain accumulation.
Tonight	Partly cloudy in the evening, becoming fair after midnight. Extremely cold. Low 12°. Wind chill ranging from 1 to 8. Wind west-northwest around 10 mph, gusting to 24 mph.
Tuesday	Mostly sunny in the morning, becoming partly to mostly cloudy in the afternoon. Cold. High 39°. Wind west-northwest around 5 mph, gusting to 23 mph, in the morning, becoming south-southwest in the afternoon.
Tuesday night	Cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Cold. Low 33°. Wind chill ranging from 25 to 35. Wind southeast around 6 mph, gusting to 23 mph, in the evening, becoming 10 mph, gusting to 22 mph, after midnight.
Wednesday	Sunny in the morning, becoming partly to mostly sunny in the afternoon. Mild. High 64°. UV index up to 4. Wind south around 8 mph, gusting to 25 mph, in the morning, becoming west-southwest in the afternoon.
Wednesday night	Partly cloudy. Low 37°. Wind northwest around 2 mph, gusting to 19 mph, in the evening, becoming south after midnight.
Thursday	Sunny. Unusually warm. High 73°. UV index up to 5. Wind south-southwest around 3 mph, gusting to 22 mph, in the morning, becoming west-northwest in the afternoon.
Thursday night	Clear in the evening, becoming mostly clear after midnight. Low 37°. Wind north near calm in the evening, becoming south after midnight.
Friday	Partly cloudy in the morning, becoming mostly sunny in the afternoon. Unusually warm. High 77°. UV index up to 5. Wind southwest around 2 mph in the morning, becoming 5 mph, gusting to 20 mph, in the afternoon.
Friday night	Clear in the evening, becoming fair to partly cloudy after midnight. Low 41°. Wind southwest around 4 mph.
Saturday	Mostly sunny. Unusually warm. High 81°. UV index up to 6. Wind west-southwest around 4 mph, gusting to 19 mph.
Saturday night	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Low 47°. Wind west around 5 mph.
Sunday	Partly to mostly sunny in the morning, becoming mostly cloudy to cloudy in the afternoon. Breezy. High 62°. UV index up to 4. Wind north around 14 mph, gusting to 31 mph.
Sunday night	Partly cloudy. Low 40°. Wind north around 11 mph, gusting to 29 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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