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: Wednesday, 23-Sep-2026 04:00 pm

Tonight Fog late	Thursday Fog a.m.	Thursday night Partly Cloudy	Friday Mostly Cloudy	Friday night Mostly Cloudy	Saturday Rain likely	Saturday night Chance rain	Sunday Rain likely
				<.1 in.	.25 in.	<.25 in.	.35 in.
Low: 54°	High: 75°	Low: 55°	High: 74°	Low: 59°	High: 66°	Low: 58°	High: 71°

NE 4-20 mph	NE 4-23 mph	NE 2-17 mph	E 3-21 mph	E 5-18 mph	E 3 mph	E 4 mph	E 4-20 mph
	UV: 6 High		UV: 4 Medium				UV: 5 Medium

Tonight	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Patchy light fog after midnight. Low 54°. Wind northeast around 4 mph, gusting to 20 mph.
Thursday	Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Patchy light fog in the morning. High 75°. UV index up to 6. Wind northeast around 4 mph, gusting to 23 mph.
Thursday night	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Low 55°. Wind northeast around 2 mph, gusting to 17 mph.
Friday	Cloudy in the morning, becoming mostly cloudy in the afternoon. High 74°. UV index up to 4. Wind east around 3 mph, gusting to 21 mph.
Friday night	Mostly cloudy to cloudy in the evening, becoming cloudy after midnight. A chance of rain. Low 59°. Wind east around 5 mph, gusting to 18 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Saturday	Dense overcast. Patchy light fog in the morning. Rain likely. High 66°. Wind east around 3 mph. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Saturday night	Cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Patchy light fog after midnight. A chance of rain. Low 58°. Wind east around 4 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Sunday	Mostly cloudy in the morning, becoming partly cloudy in the afternoon. Light to moderate fog in the morning. Rain likely. High 71°. UV index up to 5. Wind east around 4 mph, gusting to 20 mph. Chance of precipitation 60 percent. Precipitation mostly between a quarter and half an inch.
Sunday night	Fair to partly cloudy in the evening, becoming mostly cloudy after midnight. Light to moderate fog. A slight chance of rain. Low 59°. Wind east around 3 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.
Monday	Partly to mostly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Patchy light fog in the morning. High 76°. UV index up to 6. Wind east around 4 mph, gusting to 21 mph.
Monday night	Partly cloudy in the evening, becoming partly to mostly cloudy after midnight. Patchy light fog after midnight. Low 58°. Wind east around 3 mph, gusting to 15 mph.
Tuesday	Mostly cloudy to cloudy in the morning, becoming cloudy in the afternoon. Patchy light fog in the morning. A slight chance of rain in the morning, then a chance of rain in the afternoon. Scattered thundershowers possible. Warm. High 78°. Wind southeast around 7 mph, gusting to 20 mph, in the morning, becoming south around 11 mph, gusting to 23 mph, in the afternoon. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Tuesday night	Dense overcast in the evening, becoming cloudy after midnight. Patchy light fog. Rain likely in the evening, then a chance of rain after midnight. Scattered thundershowers possible. Low 63°. Wind southwest around 11 mph, gusting to 19 mph, in the evening, becoming northwest around 7 mph, gusting to 19 mph, after midnight. Chance of precipitation 80 percent. Precipitation mostly between half an inch and one inch.

WXSIM forecast formatting script by Saratoga-Weather.org.

Powered by Davis Vantage Pro2 and CumulusMX v 4.6.4 (b4128) MXUI Template v 2.2.6 by Silver Acorn Valid HTML5