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, 21-Mar-2026 05:00 am

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

High: 87°	Low: 53°	High: 86°	Low: 40°	High: 60°	Low: 41°	High: 67°	Low: 39°

SSE 4-22 mph	S 4→7 mph	SW→NW 8-28 mph	NNW 13-30→9-26 mph	NNE 7-27 mph	ENE 4-20 mph	SE 5-24 mph	SSE 5-21 mph
UV: 6 High		UV: 5 Medium		UV: 5 Medium		UV: 5 Medium

Today	Sunny. Near record warmth. High 87°. UV index up to 6. Wind south-southeast around 4 mph, gusting to 22 mph.
Tonight	Clear in the evening, becoming mostly clear after midnight. Low 53°. Wind south around 4 mph in the evening, becoming 7 mph after midnight.
Sunday	Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. Exceptionally hot. High 86°. UV index up to 5. Wind southwest around 8 mph, gusting to 28 mph, in the morning, becoming northwest in the afternoon.
Sunday night	Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Low 40°. Wind north-northwest around 13 mph, gusting to 30 mph, in the evening, becoming 9 mph, gusting to 26 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 in the evening, becoming cloudy after midnight. Low 41°. Wind east-northeast around 4 mph, gusting to 20 mph.
Tuesday	Partly cloudy. Mild. High 67°. UV index up to 5. Wind southeast around 5 mph, gusting to 24 mph.
Tuesday night	Partly cloudy. Low 39°. Wind south-southeast around 5 mph, gusting to 21 mph.
Wednesday	Partly cloudy. Unusually warm. High 75°. UV index up to 6. Wind south around 7 mph, gusting to 25 mph.
Wednesday night	Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Low 45°. Wind south-southwest around 5 mph, gusting to 18 mph.
Thursday	Mostly sunny. Exceptionally hot. High 87°. UV index up to 7. Wind west-southwest around 5 mph, gusting to 21 mph, in the morning, becoming 9 mph, gusting to 26 mph, in the afternoon.
Thursday night	Cloudy in the evening, becoming dense overcast after midnight. A chance of rain. Scattered thunderstorms likely. Breezy. Low 48°. Wind north-northeast around 11 mph, gusting to 27 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Friday	Dense overcast. Rain likely. High 50°, but temperatures falling in the afternoon. Wind north-northeast around 9 mph, gusting to 26 mph. Chance of precipitation 70 percent. Precipitation mostly around an inch.
Friday night	Cloudy in the evening, becoming partly cloudy after midnight. Patchy light fog. A chance of rain. Low 42°. Wind north-northeast around 5 mph, gusting to 21 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.

WXSIM forecast formatting script by Saratoga-Weather.org.

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