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, 18-Jun-2026 05:00 am

Today Partly Cloudy	Tonight Partly Cloudy	Friday Partly Cloudy	Friday night Partly Cloudy	Saturday Partly Cloudy	Saturday night Partly Cloudy	Sunday Thunder storm	Sunday night Thunder storm
						.75 in.	.35 in.
High: 88°	Low: 64°	High: 85°	Low: 63°	High: 89°	Low: 65°	High: 76°	Low: 70°

WNW 6-27 mph	WNW 3-25 mph	NW 4-24 mph	E→S 3-18 mph	NW 4-24 mph	E 5-19 mph	ESE→S 6-16 mph	SW 7-19 mph
UV: 7 High		UV: 8 Very High		UV: 8 Very High		UV: 5 Medium

Today	Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. High 88°. UV index up to 7. Wind west-northwest around 6 mph, gusting to 27 mph.
Tonight	Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Relatively cool. Low 64°. Wind west-northwest around 3 mph, gusting to 25 mph.
Friday	Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. High 85°. UV index up to 8. Wind northwest around 4 mph, gusting to 24 mph.
Friday night	Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Relatively cool. Low 63°. Wind east around 3 mph, gusting to 18 mph, in the evening, becoming south after midnight.
Saturday	Sunny in the morning, becoming partly cloudy in the afternoon. Hot. High 89°. UV index up to 8. Wind northwest around 4 mph, gusting to 24 mph.
Saturday night	Fair to partly cloudy in the evening, becoming partly cloudy after midnight. Low 65°. Wind east around 5 mph, gusting to 19 mph.
Sunday	Dense overcast in the morning, becoming mostly cloudy to cloudy in the afternoon. Patchy light fog. Rain very likely. Thunderstorms very likely, some severe. High 76°. UV index up to 5. Wind east-southeast around 6 mph, gusting to 16 mph, in the morning, becoming south in the afternoon. Chance of precipitation 80 percent. Precipitation mostly between half an inch and one inch.
Sunday night	Cloudy. Light to moderate fog. Rain likely in the evening, then a chance of rain after midnight. Thunderstorms very likely, some severe. Low 70°. Wind southwest around 7 mph, gusting to 19 mph. Chance of precipitation 70 percent. Precipitation mostly between a quarter and half an inch.
Monday	Cloudy. A chance of rain. Scattered thunderstorms likely. High 79°. UV index up to 5. Wind north around 7 mph, gusting to 24 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Monday night	Mostly cloudy to cloudy. Low 66°. Wind northeast around 4 mph, gusting to 21 mph.
Tuesday	Mostly cloudy. High 82°. UV index up to 5. Wind east around 4 mph, gusting to 22 mph.
Tuesday night	Partly to mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Relatively cool. Low 65°. Wind north around 5 mph, gusting to 19 mph.
Wednesday	Mostly cloudy to cloudy in the morning, becoming partly cloudy in the afternoon. A chance of rain. High 78°. UV index up to 9. Wind north around 6 mph, gusting to 26 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Wednesday night	Clear. Patchy light fog after midnight. Relatively cool. Low 61°. Wind north-northeast around 3 mph, gusting to 20 mph, in the evening, becoming east after midnight.

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