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: Sunday, 22-Mar-2026 05:00 am

Today Mostly Cloudy	Tonight Partly Cloudy	Monday Partly Cloudy	Monday night Mostly Cloudy	Tuesday Partly Cloudy	Tuesday night Partly Cloudy	Wednesday Partly Cloudy	Wednesday night Partly Cloudy

High: 90°	Low: 42°	High: 60°	Low: 38°	High: 68°	Low: 41°	High: 78°	Low: 50°

WSW→NW 6-26→9-33 mph	N 13-33→10-27 mph	NNE 7-27 mph	NE→ESE 5-23 mph	SE 6-25 mph	SSE 5-21 mph	S 5-21→8-25 mph	SSW 8-19 mph
UV: 5 Medium		UV: 5 Medium		UV: 5 Medium		UV: 6 High

Today	Partly to mostly sunny in the morning, becoming partly to mostly cloudy in the afternoon. Near record warmth. High 90°. UV index up to 5. Wind west-southwest around 6 mph, gusting to 26 mph, in the morning, becoming northwest around 9 mph, gusting to 33 mph, in the afternoon.
Tonight	Fair to partly cloudy in the evening, becoming partly cloudy after midnight. Breezy. Low 42°. Wind north around 13 mph, gusting to 33 mph, in the evening, becoming 10 mph, gusting to 27 mph, after midnight.
Monday	Partly cloudy. High 60°. UV index up to 5. Wind north-northeast around 7 mph, gusting to 27 mph.
Monday night	Partly to mostly cloudy. Low 38°. Wind northeast around 5 mph, gusting to 23 mph, in the evening, becoming east-southeast after midnight.
Tuesday	Sunny in the morning, becoming partly cloudy in the afternoon. Mild. High 68°. UV index up to 5. Wind southeast around 6 mph, gusting to 25 mph.
Tuesday night	Partly to mostly cloudy in the evening, becoming fair to partly cloudy after midnight. Low 41°. Wind south-southeast around 5 mph, gusting to 21 mph.
Wednesday	Partly to mostly sunny in the morning, becoming partly cloudy in the afternoon. Unusually warm. High 78°. UV index up to 6. Wind south around 5 mph, gusting to 21 mph, in the morning, becoming 8 mph, gusting to 25 mph, in the afternoon.
Wednesday night	Partly cloudy in the evening, becoming mostly clear after midnight. Low 50°. Wind south-southwest around 8 mph, gusting to 19 mph.
Thursday	Sunny in the morning, becoming mostly sunny in the afternoon. Near record warmth. High 92°. UV index up to 7. Wind southwest around 8 mph, gusting to 24 mph, in the morning, becoming 12 mph, gusting to 29 mph, in the afternoon.
Thursday night	Mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Patchy light fog after midnight. A chance of rain in the evening, then rain likely after midnight. Precipitation showery or intermittent. Low 49°. Wind west around 11 mph, gusting to 25 mph, in the evening, becoming north after midnight. Chance of precipitation 70 percent. Precipitation mostly around half an inch.
Friday	Mostly cloudy in the morning, becoming partly cloudy in the afternoon. A chance of rain. High 59°. UV index up to 6. Wind north around 10 mph, gusting to 30 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Friday night	Mostly clear in the evening, becoming partly cloudy after midnight. Low 40°. Wind north around 3 mph, gusting to 25 mph, in the evening, becoming west-northwest after midnight.
Saturday	Sunny. High 59°. UV index up to 7. Wind west around 5 mph, gusting to 28 mph, in the morning, becoming 11 mph, gusting to 29 mph, in the afternoon.
Saturday night	Clear in the evening, becoming fair after midnight. Low 40°. Wind north-northwest around 3 mph, gusting to 25 mph, in the evening, becoming east after midnight.

WXSIM forecast formatting script by Saratoga-Weather.org.

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