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, 20-Jun-2026 05:00 am

Today Mostly Sunny	Tonight Partly Cloudy	Sunday Thunder storm	Sunday night Thunder storm	Monday Fog a.m.	Monday night Fog late	Tuesday Fog a.m.	Tuesday night Mostly Cloudy
		.35 in.	.25 in.
High: 88°	Low: 65°	High: 80°	Low: 70°	High: 82°	Low: 63°	High: 83°	Low: 66°

N 3-23 mph	E 5-20 mph	SSE 7-19→11-23 mph	WSW→NW 10-20→6-23 mph	N 6-25 mph	NE 4-22 mph	NE 4-23 mph	ENE→ESE 3-20 mph
UV: 9 Very High		UV: 5 Medium		UV: 6 High		UV: 7 High

Today	Partly to mostly sunny. High 88°. UV index up to 9. Wind north around 3 mph, gusting to 23 mph.
Tonight	Partly cloudy in the evening, becoming partly to mostly cloudy after midnight. Relatively cool. Low 65°. Wind east around 5 mph, gusting to 20 mph.
Sunday	Dense overcast in the morning, becoming cloudy in the afternoon. A chance of rain in the morning, then rain likely in the afternoon. Scattered thunderstorms likely. High 80°. UV index up to 5. Wind south-southeast around 7 mph, gusting to 19 mph, in the morning, becoming 11 mph, gusting to 23 mph, in the afternoon. Chance of precipitation 70 percent. Precipitation mostly between a quarter and half an inch.
Sunday night	Mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Light to moderate fog. A chance of rain in the evening, then a slight chance of rain after midnight. Scattered thunderstorms likely. Low 70°. Wind west-southwest around 10 mph, gusting to 20 mph, in the evening, becoming northwest around 6 mph, gusting to 23 mph, after midnight. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Monday	Mostly cloudy to cloudy in the morning, becoming mostly cloudy in the afternoon. Patchy light fog in the morning. High 82°. UV index up to 6. Wind north around 6 mph, gusting to 25 mph.
Monday night	Fair to partly cloudy in the evening, becoming partly cloudy after midnight. Patchy light fog after midnight. Relatively cool. Low 63°. Wind northeast around 4 mph, gusting to 22 mph.
Tuesday	Partly to mostly sunny in the morning, becoming partly cloudy in the afternoon. Patchy light fog in the morning. High 83°. UV index up to 7. Wind northeast around 4 mph, gusting to 23 mph.
Tuesday night	Mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Low 66°. Wind east-northeast around 3 mph, gusting to 20 mph, in the evening, becoming east-southeast after midnight.
Wednesday	Partly to mostly cloudy in the morning, becoming partly to mostly sunny in the afternoon. A chance of rain. Scattered thundershowers possible. High 84°. UV index up to 8. Wind west-northwest around 2 mph, gusting to 22 mph, in the morning, becoming 6 mph, gusting to 24 mph, in the afternoon. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Wednesday night	Mostly clear in the evening, becoming partly to mostly cloudy after midnight. Patchy light fog after midnight. A slight chance of rain after midnight. Relatively cool. Low 64°. Wind west-northwest around 4 mph, gusting to 22 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.
Thursday	Partly to mostly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Patchy light fog in the morning. A chance of rain in the morning, then a slight chance of rain in the afternoon. High 83°. UV index up to 8. Wind north-northwest around 5 mph, gusting to 23 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Thursday night	Fair in the evening, becoming mostly clear after midnight. Patchy light fog after midnight. Relatively cool. Low 62°. Wind north-northeast around 2 mph, gusting to 21 mph.
Friday	Partly to mostly cloudy in the morning, becoming dense overcast in the afternoon. Patchy light fog in the morning. A slight chance of rain in the morning, then a chance of rain in the afternoon. Scattered thunderstorms likely. High 79°. UV index up to 5. Wind east-southeast around 4 mph, gusting to 17 mph. Chance of precipitation 50 percent. Precipitation mostly less than a tenth of an inch.
Friday night	Dense overcast. Patchy light fog. Rain very likely. Scattered thunderstorms likely. Low 69°. Wind southeast around 6 mph, gusting to 17 mph, in the evening, becoming 9 mph, gusting to 18 mph, after midnight. Chance of precipitation 90 percent. Precipitation mostly between 2 and 3 inches.

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