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, 19-Apr-2026 05:00 am

Today Sunny	Tonight Mostly Clear	Monday Sunny	Monday night Partly Cloudy	Tuesday Partly Cloudy	Tuesday night Mostly Clear	Wednesday Mostly Cloudy	Wednesday night Partly Cloudy

High: 63°	Low: 40°	High: 69°	Low: 46°	High: 78°	Low: 50°	High: 79°	Low: 52°

WSW→WNW 6-28→12-28 mph	N→NE 4-23 mph	SE 6-26 mph	S 6-22 mph	SSW 9-29→12-30 mph	SSW 8-25 mph	SW 7-26 mph	SSW 6-19 mph
UV: 7 High		UV: 7 High		UV: 7 High		UV: 6 High

Today	Sunny. High 63°. UV index up to 7. Wind west-southwest around 6 mph, gusting to 28 mph, in the morning, becoming west-northwest around 12 mph, gusting to 28 mph, in the afternoon.
Tonight	Mostly clear in the evening, becoming fair after midnight. Cool. Low 40°. Wind north around 4 mph, gusting to 23 mph, in the evening, becoming northeast after midnight.
Monday	Sunny. High 69°. UV index up to 7. Wind southeast around 6 mph, gusting to 26 mph.
Monday night	Fair in the evening, becoming partly cloudy after midnight. Low 46°. Wind south around 6 mph, gusting to 22 mph.
Tuesday	Partly cloudy in the morning, becoming sunny in the afternoon. Warm. High 78°. UV index up to 7. Wind south-southwest around 9 mph, gusting to 29 mph, in the morning, becoming 12 mph, gusting to 30 mph, in the afternoon.
Tuesday night	Clear in the evening, becoming mostly clear after midnight. Low 50°. Wind south-southwest around 8 mph, gusting to 25 mph.
Wednesday	Mostly sunny in the morning, becoming partly to mostly cloudy in the afternoon. Warm. High 79°. UV index up to 6. Wind southwest around 7 mph, gusting to 26 mph.
Wednesday night	Partly cloudy in the evening, becoming mostly clear after midnight. Low 52°. Wind south-southwest around 6 mph, gusting to 19 mph.
Thursday	Partly to mostly cloudy in the morning, becoming mostly cloudy in the afternoon. Breezy and warm. High 81°. UV index up to 5. Wind south around 9 mph, gusting to 27 mph, in the morning, becoming 14 mph, gusting to 30 mph, in the afternoon.
Thursday night	Mostly cloudy to cloudy in the evening, becoming dense overcast after midnight. Patchy light fog after midnight. A chance of rain in the evening, then rain likely after midnight. Severe thunderstorms likely, with possible tornados. Low 61°. Wind south around 9 mph, gusting to 26 mph. Chance of precipitation 80 percent. Precipitation mostly around half an inch.
Friday	Partly to mostly cloudy in the morning, becoming sunny in the afternoon. Light to moderate fog in the morning. A chance of rain. Thunderstorms very likely, some possibly severe. Warm. High 75°. UV index up to 7. Wind northwest around 7 mph, gusting to 26 mph. Chance of precipitation 50 percent. Precipitation mostly around a quarter of an inch.
Friday night	Mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Low 56°. Wind north-northeast around 6 mph, gusting to 23 mph.
Saturday	Cloudy in the morning, becoming mostly cloudy in the afternoon. High 70°. UV index up to 8. Wind north-northeast around 8 mph, gusting to 27 mph.
Saturday night	Partly cloudy in the evening, becoming fair after midnight. Low 50°. Wind north-northeast around 6 mph, gusting to 23 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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