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, 26-Sep-2026 05:00 am

Today Mostly Cloudy	Tonight Mostly Cloudy	Sunday Partly Cloudy	Sunday night Fog late	Monday Fog a.m.	Monday night Partly Cloudy	Tuesday Partly Cloudy	Tuesday night Chance rain
<.1 in.							<.1 in.
High: 76°	Low: 60°	High: 80°	Low: 56°	High: 78°	Low: 55°	High: 82°	Low: 63°

ESE 3-22 mph	ESE 2-18 mph	E 3-22 mph	ENE 3-16 mph	ENE 3-21 mph	ENE→SE 3 mph	SSE 5-22 mph	SE→S 5-15 mph
UV: 4 Medium		UV: 6 High		UV: 5 Medium		UV: 5 Medium

Today	Mostly cloudy to cloudy. A chance of rain. High 76°. UV index up to 4. Wind east-southeast around 3 mph, gusting to 22 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Tonight	Mostly cloudy to cloudy in the evening, becoming mostly cloudy after midnight. Low 60°. Wind east-southeast around 2 mph, gusting to 18 mph.
Sunday	Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Warm. High 80°. UV index up to 6. Wind east around 3 mph, gusting to 22 mph.
Sunday night	Fair in the evening, becoming fair to partly cloudy after midnight. Patchy light fog after midnight. Low 56°. Wind east-northeast around 3 mph, gusting to 16 mph.
Monday	Partly to mostly sunny in the morning, becoming partly cloudy in the afternoon. Patchy light fog in the morning. Warm. High 78°. UV index up to 5. Wind east-northeast around 3 mph, gusting to 21 mph.
Monday night	Mostly clear in the evening, becoming partly cloudy after midnight. Low 55°. Wind east-northeast around 3 mph in the evening, becoming southeast after midnight.
Tuesday	Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. Warm. High 82°. UV index up to 5. Wind south-southeast around 5 mph, gusting to 22 mph.
Tuesday night	Mostly cloudy to cloudy in the evening, becoming cloudy after midnight. A slight chance of rain in the evening, then a chance of rain after midnight. Precipitation showery or intermittent. Low 63°. Wind southeast around 5 mph, gusting to 15 mph, in the evening, becoming south after midnight. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch.
Wednesday	Dense overcast. Patchy light fog in the afternoon. A chance of rain in the morning, then rain likely in the afternoon. Scattered thundershowers possible. High 73°. Wind south around 5 mph, gusting to 16 mph. Chance of precipitation 80 percent. Precipitation mostly around half an inch.
Wednesday night	Dense overcast in the evening, becoming mostly cloudy to cloudy after midnight. Patchy light fog in the evening, then light to moderate fog after midnight. Rain likely. Scattered thundershowers possible. Warm. Low 67°. Wind south-southeast around 4 mph. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Thursday	Partly cloudy in the morning, becoming cloudy in the afternoon. Light to moderate fog. A slight chance of rain in the morning, then rain likely in the afternoon. Scattered thunderstorms likely. Warm. High 82°. UV index up to 4. Wind south-southeast around 7 mph, gusting to 20 mph, in the morning, becoming southwest in the afternoon. Chance of precipitation 60 percent. Precipitation mostly between a quarter and half an inch.
Thursday night	Dense overcast in the evening, becoming cloudy after midnight. Light to moderate fog. Rain likely in the evening, then a chance of rain after midnight. Scattered thunderstorms likely. Warm. Low 70°. Wind southwest around 3 mph in the evening, becoming south after midnight. Chance of precipitation 70 percent. Precipitation mostly between a quarter and half an inch.
Friday	Dense overcast. Patchy light fog. Rain likely. Scattered thunderstorms likely. High 74°. Wind south around 5 mph, gusting to 17 mph. Chance of precipitation 70 percent. Precipitation mostly around a quarter of an inch.
Friday night	Dense overcast. Patchy light fog. A chance of rain in the evening, then a slight chance of rain after midnight. Scattered thundershowers possible. Warm. Low 68°. Wind west-southwest around 3 mph in the evening, becoming north after midnight. Chance of precipitation 50 percent. Precipitation mostly less than a tenth of an inch.

WXSIM forecast formatting script by Saratoga-Weather.org.

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