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: Friday, 28-Aug-2026 05:00 am

Today Sunny	Tonight Mostly Clear	Saturday Partly Cloudy	Saturday night Partly Cloudy	Sunday Mostly Sunny	Sunday night Partly Cloudy	Monday Mostly Sunny	Monday night Partly Cloudy

High: 85°	Low: 59°	High: 88°	Low: 63°	High: 93°	Low: 67°	High: 95°	Low: 69°
						Heat: 99°
NNE 3-21 mph	ESE 2 mph	SSE 5-23 mph	SSE 5-17 mph	SSE 7-24 mph	SSE 6-16 mph	SSE→SSW 6-20 mph	S 6 mph
UV: 7 High		UV: 7 High		UV: 8 Very High		UV: 7 High

Today	Sunny. High 85°. UV index up to 7. Wind north-northeast around 3 mph, gusting to 21 mph.
Tonight	Mostly clear in the evening, becoming fair after midnight. Relatively cool. Low 59°. Wind east-southeast around 2 mph.
Saturday	Partly to mostly sunny in the morning, becoming partly cloudy in the afternoon. Hot. High 88°. UV index up to 7. Wind south-southeast around 5 mph, gusting to 23 mph.
Saturday night	Partly cloudy in the evening, becoming fair after midnight. Low 63°. Wind south-southeast around 5 mph, gusting to 17 mph.
Sunday	Mostly sunny in the morning, becoming sunny in the afternoon. Very hot. High 93°. UV index up to 8. Wind south-southeast around 7 mph, gusting to 24 mph.
Sunday night	Fair to partly cloudy in the evening, becoming mostly clear after midnight. Low 67°. Wind south-southeast around 6 mph, gusting to 16 mph.
Monday	Partly to mostly sunny. Very hot. High 95°. Heat index up to 99°. UV index up to 7. Wind south-southeast around 6 mph, gusting to 20 mph, in the morning, becoming south-southwest in the afternoon.
Monday night	Fair to partly cloudy in the evening, becoming clear after midnight. Low 69°. Wind south around 6 mph.
Tuesday	Sunny. Patchy light fog in the morning. Very hot. High 96°. Heat index up to 102°. UV index up to 8. Wind south-southwest around 6 mph, gusting to 19 mph.
Tuesday night	Clear. Patchy light fog after midnight. Low 70°. Wind south around 7 mph.
Wednesday	Sunny. Patchy light fog in the morning. Very hot. High 96°. Heat index up to 103°. UV index up to 8. Wind southwest around 6 mph, gusting to 20 mph.
Wednesday night	Clear in the evening, becoming fair to partly cloudy after midnight. Low 72°. Wind southwest around 6 mph.
Thursday	Mostly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Very hot. High 98°. Heat index up to 108°. UV index up to 7. Wind southwest around 6 mph, gusting to 19 mph.
Thursday night	Mostly clear in the evening, becoming clear after midnight. Low 72°. Wind south-southwest around 5 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