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, 19-Oct-2026 04:00 pm

Tonight Partly Cloudy	Tuesday Mostly Sunny	Tuesday night Fair	Wednesday Partly Cloudy	Wednesday night Clear	Thursday Sunny	Thursday night Clear	Friday Sunny

Low: 45°	High: 71°	Low: 46°	High: 72°	Low: 44°	High: 71°	Low: 47°	High: 72°

E→SSE 2-18 mph	SE 2-20 mph	ESE→SSE 2 mph	S→ESE 2-20 mph	ESE→SW calm	ESE 1-18 mph	ESE 2 mph	ESE 5-23 mph
	UV: 4 Medium		UV: 4 Medium		UV: 4 Medium		UV: 5 Medium

Tonight	Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Low 45°. Wind east around 2 mph, gusting to 18 mph, in the evening, becoming south-southeast after midnight.
Tuesday	Partly to mostly sunny in the morning, becoming mostly sunny in the afternoon. Mild. High 71°. UV index up to 4. Wind southeast around 2 mph, gusting to 20 mph.
Tuesday night	Fair. Low 46°. Wind east-southeast around 2 mph in the evening, becoming south-southeast after midnight.
Wednesday	Partly cloudy in the morning, becoming mostly sunny in the afternoon. Mild. High 72°. UV index up to 4. Wind south around 2 mph, gusting to 20 mph, in the morning, becoming east-southeast in the afternoon.
Wednesday night	Clear. Low 44°. Wind east-southeast near calm in the evening, becoming southwest after midnight.
Thursday	Sunny. Mild. High 71°. UV index up to 4. Wind east-southeast around 1 mph, gusting to 18 mph.
Thursday night	Clear. Low 47°. Wind east-southeast around 2 mph.
Friday	Sunny. Warm. High 72°. UV index up to 5. Wind east-southeast around 5 mph, gusting to 23 mph.
Friday night	Clear in the evening, becoming fair after midnight. Patchy light fog. Low 47°. Wind east-southeast around 5 mph, gusting to 15 mph.
Saturday	Mostly sunny in the morning, becoming partly cloudy in the afternoon. Patchy light fog in the morning. Mild. High 71°. UV index up to 4. Wind east-southeast around 5 mph, gusting to 22 mph.
Saturday night	Fair to partly cloudy in the evening, becoming partly cloudy after midnight. Low 47°. Wind east-southeast around 4 mph in the evening, becoming south-southeast after midnight.
Sunday	Partly to mostly cloudy. Warm. High 76°. Wind south-southwest around 6 mph, gusting to 19 mph.
Sunday night	Cloudy. Low 55°. Wind southwest around 3 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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