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: Monday, 11-May-2026 04:00 pm

Tonight Clear	Tuesday Sunny	Tuesday night Fog late	Wednesday Sunny	Wednesday night Clear	Thursday Mostly Sunny	Thursday night Partly Cloudy	Friday Chance rain
		<.1 in.					<.25 in.
Low: 51°	High: 81°	Low: 58°	High: 75°	Low: 51°	High: 75°	Low: 53°	High: 75°

S 3-23 mph	SW 6-24→10-28 mph	W 8-22 mph	NW 9-29 mph	NNW→NE 4-24 mph	ESE 5-25 mph	ESE 8-24 mph	S 12-27 mph
	UV: 8 Very High		UV: 7 High		UV: 8 Very High		UV: 5 Medium

Tonight	Clear. Cool. Low 51°. Wind south around 3 mph, gusting to 23 mph.
Tuesday	Sunny. Warm. High 81°. UV index up to 8. Wind southwest around 6 mph, gusting to 24 mph, in the morning, becoming 10 mph, gusting to 28 mph, in the afternoon.
Tuesday night	Partly to mostly cloudy in the evening, becoming clear after midnight. Patchy light fog after midnight. A chance of rain in the evening, then a slight chance of rain after midnight. Low 58°. Wind west around 8 mph, gusting to 22 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Wednesday	Sunny. High 75°. UV index up to 7. Wind northwest around 9 mph, gusting to 29 mph.
Wednesday night	Clear. Cool. Low 51°. Wind north-northwest around 4 mph, gusting to 24 mph, in the evening, becoming northeast after midnight.
Thursday	Sunny in the morning, becoming partly to mostly sunny in the afternoon. High 75°. UV index up to 8. Wind east-southeast around 5 mph, gusting to 25 mph.
Thursday night	Partly cloudy. Cool. Low 53°. Wind east-southeast around 8 mph, gusting to 24 mph.
Friday	Mostly cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. A chance of rain. Breezy. High 75°. UV index up to 5. Wind south around 12 mph, gusting to 27 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Friday night	Mostly cloudy in the evening, becoming fair after midnight. Moderate fog. A chance of rain in the evening, then a slight chance of rain after midnight. Precipitation showery or intermittent. Low 60°. Wind south-southwest around 5 mph, gusting to 18 mph, in the evening, becoming west after midnight. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Saturday	Sunny. Light to moderate fog in the morning. Warm. High 84°. UV index up to 8. Wind west around 5 mph, gusting to 21 mph.
Saturday night	Fair in the evening, becoming partly to mostly cloudy after midnight. Moderate fog after midnight. Low 60°. Wind southeast around 5 mph.
Sunday	Sunny in the morning, becoming partly cloudy in the afternoon. Light to moderate fog in the morning. Unusually hot. High 90°. UV index up to 9. Wind south around 9 mph, gusting to 27 mph.
Sunday night	Clear in the evening, becoming fair after midnight. Low 64°. Wind south around 9 mph, gusting to 23 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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