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, 13-Aug-2025 05:00 am

Today Mostly Sunny	Tonight Fog late	Thursday Fog a.m.	Thursday night Mostly Clear	Friday Mostly Sunny	Friday night Fog late	Saturday Fog a.m.	Saturday night Fog late

High: 85°	Low: 64°	High: 84°	Low: 66°	High: 89°	Low: 70°	High: 91°	Low: 71°
				Heat: 94°		Heat: 98°
N 3-21 mph	N 3-15 mph	NE 3-18 mph	ENE→SE 4 mph	SSE→SSW 4-16 mph	SE 4 mph	SSE 4-16 mph	ESE→S 4 mph
UV: 8 Very High		UV: 7 High		UV: 9 Very High		UV: 8 Very High

Today	Sunny in the morning, becoming partly to mostly sunny in the afternoon. High 85°. UV index up to 8. Wind north around 3 mph, gusting to 21 mph.
Tonight	Mostly clear in the evening, becoming clear after midnight. Patchy light fog after midnight. Relatively cool. Low 64°. Wind north around 3 mph, gusting to 15 mph.
Thursday	Mostly sunny in the morning, becoming partly to mostly sunny in the afternoon. Patchy light fog in the morning. High 84°. UV index up to 7. Wind northeast around 3 mph, gusting to 18 mph.
Thursday night	Fair in the evening, becoming mostly clear after midnight. Low 66°. Wind east-northeast around 4 mph in the evening, becoming southeast after midnight.
Friday	Partly to mostly sunny in the morning, becoming sunny in the afternoon. Hot. High 89°. Heat index up to 94°. UV index up to 9. Wind south-southeast around 4 mph, gusting to 16 mph, in the morning, becoming south-southwest in the afternoon.
Friday night	Mostly clear in the evening, becoming clear after midnight. Patchy light fog after midnight. Low 70°. Wind southeast around 4 mph.
Saturday	Sunny. Patchy light fog in the morning. Hot. High 91°. Heat index up to 98°. UV index up to 8. Wind south-southeast around 4 mph, gusting to 16 mph.
Saturday night	Clear. Patchy light fog after midnight. Low 71°. Wind east-southeast around 4 mph in the evening, becoming south after midnight.
Sunday	Sunny. Patchy light fog in the morning. Hot. High 93°. Heat index up to 102°. UV index up to 7. Wind south-southeast around 3 mph, gusting to 16 mph.
Sunday night	Clear. Patchy light fog after midnight. Low 72°. Wind south-southeast around 4 mph.
Monday	Sunny. Patchy light fog in the morning. Hot. High 92°. Heat index up to 102°. UV index up to 8. Wind south-southwest around 3 mph, gusting to 15 mph.
Monday night	Mostly clear in the evening, becoming partly to mostly cloudy after midnight. Low 73°. Wind south around 3 mph.
Tuesday	Mostly sunny in the morning, becoming partly to mostly cloudy in the afternoon. A chance of rain in the afternoon. Scattered thundershowers possible. Hot. High 90°. Heat index up to 96°. UV index up to 6. Wind west-northwest around 4 mph, gusting to 20 mph, in the morning, becoming north in the afternoon. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Tuesday night	Mostly cloudy to cloudy in the evening, becoming cloudy after midnight. Light to moderate fog. Rain likely in the evening, then a slight chance of rain after midnight. Scattered thundershowers possible. Low 73°. Wind southwest around 7 mph, gusting to 20 mph, in the evening, becoming north-northeast around 3 mph after midnight. Chance of precipitation 70 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 4.4.5 (b4088) MXUI Template v 2.2.6 by Silver Acorn Valid HTML5