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, 20-Apr-2026 05:00 am

Today Sunny	Tonight Partly Cloudy	Tuesday Partly Cloudy	Tuesday night Fog late	Wednesday Fog a.m.	Wednesday night Fog late	Thursday Fog a.m.	Thursday night Thunder storm
							<.25 in.
High: 70°	Low: 45°	High: 78°	Low: 50°	High: 75°	Low: 53°	High: 79°	Low: 59°

ESE 5-25 mph	SE→SSW 5-20 mph	SSW 8-26→12-30 mph	SW 8-26 mph	SW 7-25 mph	S 5-17 mph	S 8-25→13-28 mph	S 9-24 mph
UV: 7 High		UV: 7 High		UV: 7 High		UV: 6 High

Today	Sunny. High 70°. UV index up to 7. Wind east-southeast around 5 mph, gusting to 25 mph.
Tonight	Clear in the evening, becoming fair to partly cloudy after midnight. Low 45°. Wind southeast around 5 mph, gusting to 20 mph, in the evening, becoming south-southwest after midnight.
Tuesday	Partly cloudy in the morning, becoming sunny in the afternoon. Warm. High 78°. UV index up to 7. Wind south-southwest around 8 mph, gusting to 26 mph, in the morning, becoming 12 mph, gusting to 30 mph, in the afternoon.
Tuesday night	Clear in the evening, becoming fair after midnight. Patchy light fog after midnight. Low 50°. Wind southwest around 8 mph, gusting to 26 mph.
Wednesday	Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. Patchy light fog in the morning. Warm. High 75°. UV index up to 7. Wind southwest around 7 mph, gusting to 25 mph.
Wednesday night	Partly to mostly cloudy in the evening, becoming fair after midnight. Patchy light fog after midnight. Low 53°. Wind south around 5 mph, gusting to 17 mph.
Thursday	Partly to mostly sunny in the morning, becoming partly to mostly cloudy in the afternoon. Patchy light fog in the morning. Warm. High 79°. UV index up to 6. Wind south around 8 mph, gusting to 25 mph, in the morning, becoming 13 mph, gusting to 28 mph, in the afternoon.
Thursday night	Partly to mostly cloudy. Light to moderate fog after midnight. A slight chance of rain in the evening, then a chance of rain after midnight. Scattered thunderstorms likely, some possibly severe. Low 59°. Wind south around 9 mph, gusting to 24 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Friday	Dense overcast in the morning, becoming cloudy in the afternoon. Light to moderate fog. Rain very likely. Thunderstorms very likely, some severe. High 67°. Wind south-southwest around 8 mph, gusting to 18 mph. Chance of precipitation 90 percent. Precipitation mostly around an inch.
Friday night	Mostly cloudy in the evening, becoming mostly clear after midnight. Light to moderate fog in the evening, then patchy light fog after midnight. A chance of rain. Thunderstorms very likely, some possibly severe. Low 54°. Wind northwest around 6 mph, gusting to 17 mph. Chance of precipitation 50 percent. Precipitation mostly around a tenth of an inch.
Saturday	Partly to mostly sunny. Patchy light fog in the morning. High 73°. UV index up to 6. Wind north-northeast around 7 mph, gusting to 25 mph.
Saturday night	Fair to partly cloudy in the evening, becoming mostly cloudy after midnight. Low 53°. Wind north-northeast around 6 mph, gusting to 21 mph.
Sunday	Partly to mostly cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. High 70°. UV index up to 7. Wind northeast around 6 mph, gusting to 24 mph.
Sunday night	Dense overcast. Patchy light fog after midnight. A chance of rain in the evening, then rain likely after midnight. Scattered thundershowers possible. Low 54°. Wind east-northeast around 5 mph, gusting to 17 mph, in the evening, becoming 9 mph, gusting to 20 mph, after midnight. Chance of precipitation 80 percent. Precipitation mostly around half an inch.

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