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: Thursday, 12-Mar-2026 04:00 pm

Tonight Partly Cloudy	Friday Partly Cloudy	Friday night Partly Cloudy	Saturday Partly Cloudy	Saturday night Mostly Cloudy	Sunday Thunder storm	Sunday night Rain and Snow	Monday Mostly Cloudy
					.35 in.	.35 in.
Low: 40°	High: 59°	Low: 36°	High: 64°	Low: 47°	High: 65°	Low: 27°	High: 29°
WCh: 31°						WCh: 18°	WCh: 13°
SSW 11-26→16-24 mph	WNW 14-29→11-29 mph	NW→ENE 4-21 mph	ESE 9-27 mph	SSE 9-21 mph	SSE→WSW 13-27→16-29 mph	WNW 17-36 mph	NW 16-34 mph
			UV: 5 Medium

Tonight	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Breezy. Low 40°. Wind chill ranging from 31 to 47. Wind south-southwest around 11 mph, gusting to 26 mph, in the evening, becoming 16 mph, gusting to 24 mph, after midnight.
Friday	Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. Breezy. High 59°. Wind west-northwest around 14 mph, gusting to 29 mph, in the morning, becoming 11 mph, gusting to 29 mph, in the afternoon.
Friday night	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Low 36°. Wind northwest around 4 mph, gusting to 21 mph, in the evening, becoming east-northeast after midnight.
Saturday	Partly cloudy. Mild. High 64°. UV index up to 5. Wind east-southeast around 9 mph, gusting to 27 mph.
Saturday night	Mostly cloudy. Low 47°. Wind south-southeast around 9 mph, gusting to 21 mph.
Sunday	Mostly cloudy to cloudy in the morning, becoming dense overcast in the afternoon. A slight chance of rain in the morning, then rain likely in the afternoon. Scattered thundershowers possible. Breezy and mild. High 65°. Wind south-southeast around 13 mph, gusting to 27 mph, in the morning, becoming west-southwest around 16 mph, gusting to 29 mph, in the afternoon. Chance of precipitation 70 percent. Precipitation mostly between a quarter and half an inch.
Sunday night	Dense overcast. A mix of rain and snow likely in the evening, then a chance of a mix of rain and snow after midnight. Windy and cold. Low 27°. Wind chill ranging from 18 to 43. Wind west-northwest around 17 mph, gusting to 36 mph. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly between a quarter and half an inch. Little or no snow accumulation expected.
Monday	Cloudy in the morning, becoming mostly cloudy in the afternoon. Windy and very cold. High 29°, but temperatures falling in the afternoon. Wind chill ranging from 13 to 18. Wind northwest around 16 mph, gusting to 34 mph.
Monday night	Mostly clear in the evening, becoming clear after midnight. Very cold. Low 20°. Wind chill as low as 11. Wind northwest around 9 mph, gusting to 27 mph.
Tuesday	Partly to mostly sunny in the morning, becoming mostly cloudy to cloudy in the afternoon. High 42°. Wind west around 4 mph, gusting to 26 mph, in the morning, becoming south in the afternoon.
Tuesday night	Cloudy in the evening, becoming mostly cloudy after midnight. Low 33°. Wind chill ranging from 27 to 37. Wind southeast around 8 mph, gusting to 22 mph.
Wednesday	Partly cloudy. Breezy and mild. High 63°. UV index up to 5. Wind south-southwest around 12 mph, gusting to 29 mph.
Wednesday night	Fair in the evening, becoming cloudy after midnight. Low 41°. Wind west around 4 mph, gusting to 22 mph, in the evening, becoming north after midnight.

WXSIM forecast formatting script by Saratoga-Weather.org.

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