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, 26-Aug-2026 05:00 am

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

High: 94°	Low: 67°	High: 86°	Low: 63°	High: 86°	Low: 61°	High: 90°	Low: 64°
Heat: 99°
SW→WNW 4-24 mph	NNW 3-21 mph	NNW 4-23 mph	NE 2-17 mph	NNE 3-22 mph	E 3-16 mph	SSE 4-22 mph	SSE 6-17 mph
UV: 8 Very High		UV: 7 High		UV: 7 High		UV: 7 High

Today	Mostly sunny in the morning, becoming sunny in the afternoon. Very hot. High 94°. Heat index up to 99°. UV index up to 8. Wind southwest around 4 mph, gusting to 24 mph, in the morning, becoming west-northwest in the afternoon.
Tonight	Clear. Low 67°. Wind north-northwest around 3 mph, gusting to 21 mph.
Thursday	Mostly sunny in the morning, becoming partly to mostly sunny in the afternoon. Hot. High 86°. UV index up to 7. Wind north-northwest around 4 mph, gusting to 23 mph.
Thursday night	Clear. Low 63°. Wind northeast around 2 mph, gusting to 17 mph.
Friday	Sunny. Patchy light fog in the morning. High 86°. UV index up to 7. Wind north-northeast around 3 mph, gusting to 22 mph.
Friday night	Fair to partly cloudy in the evening, becoming fair after midnight. Low 61°. Wind east around 3 mph, gusting to 16 mph.
Saturday	Partly to mostly sunny. Hot. High 90°. UV index up to 7. Wind south-southeast around 4 mph, gusting to 22 mph.
Saturday night	Fair in the evening, becoming partly cloudy after midnight. Low 64°. Wind south-southeast around 6 mph, gusting to 17 mph.
Sunday	Mostly sunny in the morning, becoming partly cloudy in the afternoon. Light to moderate fog in the morning. Very hot. High 94°. UV index up to 7. Wind south around 8 mph, gusting to 24 mph.
Sunday night	Fair in the evening, becoming partly cloudy after midnight. Low 68°. Wind south around 8 mph, gusting to 19 mph.
Monday	Mostly sunny in the morning, becoming sunny in the afternoon. Very hot. High 97°. Heat index up to 101°. UV index up to 8. Wind south around 8 mph, gusting to 25 mph.
Monday night	Clear. Low 68°. Wind south-southwest around 7 mph, gusting to 18 mph.
Tuesday	Sunny. Very hot. High 97°. Heat index up to 102°. UV index up to 8. Wind south-southwest around 10 mph, gusting to 26 mph.
Tuesday night	Partly cloudy in the evening, becoming clear after midnight. Low 70°. Wind south-southwest around 7 mph, gusting to 18 mph.

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