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 04:00 pm

Tonight Partly Cloudy	Monday Partly Cloudy	Monday night Mostly Cloudy	Tuesday Mostly Cloudy	Tuesday night Partly Cloudy	Wednesday Partly Cloudy	Wednesday night Partly Cloudy	Thursday Mostly Sunny

Low: 41°	High: 58°	Low: 41°	High: 67°	Low: 40°	High: 75°	Low: 47°	High: 89°

NNW 14-28→11-28 mph	N 8-27 mph	ENE 4-22 mph	SE 7-24 mph	SE 5-23 mph	S 6-22→9-26 mph	SSW 8-21 mph	SW 8-24→11-28 mph
	UV: 5 Medium		UV: 5 Medium		UV: 6 High		UV: 7 High

Tonight	Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Breezy. Low 41°. Wind north-northwest around 14 mph, gusting to 28 mph, in the evening, becoming 11 mph, gusting to 28 mph, after midnight.
Monday	Partly cloudy. High 58°. UV index up to 5. Wind north around 8 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 22 mph.
Tuesday	Mostly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Mild. High 67°. UV index up to 5. Wind southeast around 7 mph, gusting to 24 mph.
Tuesday night	Partly cloudy. Low 40°. Wind southeast around 5 mph, gusting to 23 mph.
Wednesday	Partly cloudy. Unusually warm. High 75°. UV index up to 6. Wind south around 6 mph, gusting to 22 mph, in the morning, becoming 9 mph, gusting to 26 mph, in the afternoon.
Wednesday night	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Low 47°. Wind south-southwest around 8 mph, gusting to 21 mph.
Thursday	Sunny in the morning, becoming mostly sunny in the afternoon. Near record warmth. High 89°. UV index up to 7. Wind southwest around 8 mph, gusting to 24 mph, in the morning, becoming 11 mph, gusting to 28 mph, in the afternoon.
Thursday night	Partly to mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. A slight chance of rain in the evening, then a chance of rain after midnight. Low 51°. Wind southwest around 11 mph, gusting to 22 mph, in the evening, becoming north-northwest after midnight. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Friday	Mostly cloudy in the morning, becoming partly cloudy in the afternoon. A chance of rain. High 60°. UV index up to 6. Wind north around 10 mph, gusting to 29 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Friday night	Mostly clear in the evening, becoming clear after midnight. Low 38°. Wind north around 6 mph, gusting to 26 mph.
Saturday	Sunny. High 60°. UV index up to 7. Wind west around 4 mph, gusting to 24 mph.
Saturday night	Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Low 40°. Wind south-southwest around 5 mph, gusting to 18 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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