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, 18-Apr-2026 04:00 pm

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

Low: 42°	High: 65°	Low: 40°	High: 68°	Low: 45°	High: 76°	Low: 48°	High: 79°

NW→WSW 8-26→5 mph	W 7-27→12-28 mph	N 5-25 mph	E→SE 6-26 mph	SSE 6-21 mph	SSW 8-28→12-29 mph	SW 7-24 mph	SW 7-25 mph
	UV: 6 High		UV: 6 High		UV: 7 High		UV: 6 High

Tonight	Fair to partly cloudy. Cool. Low 42°. Wind northwest around 8 mph, gusting to 26 mph, in the evening, becoming west-southwest around 5 mph after midnight.
Sunday	Mostly sunny in the morning, becoming sunny in the afternoon. High 65°. UV index up to 6. Wind west around 7 mph, gusting to 27 mph, in the morning, becoming 12 mph, gusting to 28 mph, in the afternoon.
Sunday night	Fair in the evening, becoming mostly clear after midnight. Cool. Low 40°. Wind north around 5 mph, gusting to 25 mph.
Monday	Sunny. High 68°. UV index up to 6. Wind east around 6 mph, gusting to 26 mph, in the morning, becoming southeast in the afternoon.
Monday night	Mostly clear in the evening, becoming partly cloudy after midnight. Low 45°. Wind south-southeast around 6 mph, gusting to 21 mph.
Tuesday	Partly cloudy in the morning, becoming sunny in the afternoon. Warm. High 76°. UV index up to 7. Wind south-southwest around 8 mph, gusting to 28 mph, in the morning, becoming 12 mph, gusting to 29 mph, in the afternoon.
Tuesday night	Fair in the evening, becoming fair to partly cloudy after midnight. Low 48°. Wind southwest around 7 mph, gusting to 24 mph.
Wednesday	Partly cloudy. Warm. High 79°. UV index up to 6. Wind southwest around 7 mph, gusting to 25 mph.
Wednesday night	Partly to mostly cloudy in the evening, becoming mostly clear after midnight. Low 50°. Wind south-southwest around 6 mph, gusting to 19 mph.
Thursday	Sunny in the morning, becoming mostly cloudy to cloudy in the afternoon. Breezy and warm. High 79°. UV index up to 5. Wind south around 10 mph, gusting to 30 mph, in the morning, becoming 14 mph, gusting to 31 mph, in the afternoon.
Thursday night	Mostly cloudy to cloudy in the evening, becoming mostly cloudy after midnight. A slight chance of rain in the evening, then a chance of rain after midnight. Scattered thundershowers possible. Low 57°. Wind south around 11 mph, gusting to 24 mph. Chance of precipitation 50 percent. Precipitation mostly around a tenth of an inch.
Friday	Dense overcast. Patchy light fog in the morning, then light to moderate fog in the afternoon. Rain very likely. Scattered thunderstorms likely. High 65°. Wind south around 8 mph, gusting to 24 mph, in the morning, becoming west-southwest in the afternoon. Chance of precipitation 90 percent. Precipitation mostly between 1 and 2 inches.
Friday night	Fair to partly cloudy in the evening, becoming partly cloudy after midnight. Moderate to dense fog in the evening, then patchy light fog after midnight. A chance of rain. Precipitation showery or intermittent. Low 52°. Wind northwest around 5 mph, gusting to 17 mph. Chance of precipitation 40 percent. Precipitation mostly less than a quarter of an inch.

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