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, 21-Sep-2026 04:00 pm

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

Low: 63°	High: 74°	Low: 55°	High: 75°	Low: 53°	High: 77°	Low: 56°	High: 74°

NE 4-16 mph	NE 6-24 mph	NE 6-23 mph	N 6-25 mph	NE 4-22 mph	NE 4-24 mph	NE 2-17 mph	E 4-18 mph
			UV: 6 High		UV: 6 High

Tonight	Mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Low 63°. Wind northeast around 4 mph, gusting to 16 mph.
Tuesday	Mostly cloudy to cloudy in the morning, becoming mostly cloudy in the afternoon. High 74°. Wind northeast around 6 mph, gusting to 24 mph.
Tuesday night	Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Low 55°. Wind northeast around 6 mph, gusting to 23 mph.
Wednesday	Partly to mostly sunny. High 75°. UV index up to 6. Wind north around 6 mph, gusting to 25 mph.
Wednesday night	Fair in the evening, becoming partly cloudy after midnight. Low 53°. Wind northeast around 4 mph, gusting to 22 mph.
Thursday	Mostly sunny in the morning, becoming partly to mostly sunny in the afternoon. High 77°. UV index up to 6. Wind northeast around 4 mph, gusting to 24 mph.
Thursday night	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Low 56°. Wind northeast around 2 mph, gusting to 17 mph.
Friday	Mostly cloudy in the morning, becoming cloudy in the afternoon. High 74°. Wind east around 4 mph, gusting to 18 mph.
Friday night	Mostly cloudy to cloudy in the evening, becoming mostly cloudy after midnight. Low 59°. Wind east-southeast around 4 mph.
Saturday	Cloudy. A slight chance of rain in the morning, then a chance of rain in the afternoon. High 74°. Wind east-southeast around 5 mph, gusting to 18 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Saturday night	Mostly cloudy to cloudy in the evening, becoming partly to mostly cloudy after midnight. Patchy light fog in the evening, then moderate fog after midnight. A chance of rain in the evening, then a slight chance of rain after midnight. Low 60°. Wind east-southeast around 5 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Sunday	Partly to mostly cloudy in the morning, becoming sunny in the afternoon. Patchy light fog in the morning. Warm. High 82°. UV index up to 5. Wind south around 6 mph, gusting to 22 mph, in the morning, becoming west in the afternoon.
Sunday night	Fair. Moderate fog after midnight. Low 57°. Wind north around 5 mph, gusting to 16 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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