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: Saturday, 09-May-2026 04:00 pm

Tonight Chance rain	Sunday Partly Cloudy	Sunday night Partly Cloudy	Monday Mostly Sunny	Monday night Fog late	Tuesday Fog a.m.	Tuesday night Chance rain	Wednesday Fog a.m.
.1 in.						<.25 in.
Low: 56°	High: 73°	Low: 52°	High: 75°	Low: 51°	High: 79°	Low: 55°	High: 76°

WSW→NNE 5-25 mph	NNE 7-26 mph	NNE→SSW 2-22 mph	W 5-23 mph	WSW 4-21 mph	SSW 7-26→11-28 mph	WSW 8-23 mph	WNW 9-28 mph
	UV: 6 High		UV: 7 High		UV: 8 Very High		UV: 7 High

Tonight	Mostly cloudy in the evening, becoming partly to mostly cloudy after midnight. A slight chance of rain in the evening, then a chance of rain after midnight. Precipitation showery or intermittent. Low 56°. Wind west-southwest around 5 mph, gusting to 25 mph, in the evening, becoming north-northeast after midnight. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch.
Sunday	Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. High 73°. UV index up to 6. Wind north-northeast around 7 mph, gusting to 26 mph.
Sunday night	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Low 52°. Wind north-northeast around 2 mph, gusting to 22 mph, in the evening, becoming south-southwest after midnight.
Monday	Mostly sunny in the morning, becoming sunny in the afternoon. High 75°. UV index up to 7. Wind west around 5 mph, gusting to 23 mph.
Monday night	Mostly clear in the evening, becoming clear after midnight. Patchy light fog after midnight. Cool. Low 51°. Wind west-southwest around 4 mph, gusting to 21 mph.
Tuesday	Sunny. Patchy light fog in the morning. High 79°. UV index up to 8. Wind south-southwest around 7 mph, gusting to 26 mph, in the morning, becoming 11 mph, gusting to 28 mph, in the afternoon.
Tuesday night	Partly cloudy in the evening, becoming clear after midnight. Patchy light fog. A chance of rain. Low 55°. Wind west-southwest around 8 mph, gusting to 23 mph. Chance of precipitation 40 percent. Precipitation mostly less than a quarter of an inch.
Wednesday	Sunny. Patchy light fog in the morning. High 76°. UV index up to 7. Wind west-northwest around 9 mph, gusting to 28 mph.
Wednesday night	Clear. Cool. Low 49°. Wind north around 4 mph, gusting to 23 mph, in the evening, becoming east-northeast after midnight.
Thursday	Sunny. High 78°. UV index up to 8. Wind east-southeast around 5 mph, gusting to 27 mph.
Thursday night	Fair in the evening, becoming partly cloudy after midnight. Cool. Low 52°. Wind east-southeast around 9 mph, gusting to 24 mph.
Friday	Partly to mostly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Breezy and hot. High 86°. UV index up to 9. Wind south around 13 mph, gusting to 30 mph.
Friday night	Mostly clear in the evening, becoming mostly cloudy after midnight. Low 59°. Wind south-southwest around 11 mph, gusting to 27 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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