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, 20-Sep-2026 04:00 pm

Tonight Rain likely	Monday Mostly Cloudy	Monday night Mostly Cloudy	Tuesday Mostly Cloudy	Tuesday night Mostly Cloudy	Wednesday Fog a.m.	Wednesday night Partly Cloudy	Thursday Fog a.m.
.25 in.	<.1 in.
Low: 71°	High: 77°	Low: 66°	High: 75°	Low: 57°	High: 74°	Low: 53°	High: 76°

NNE 6-20→3 mph	NNE 4-23 mph	NNE 5-22 mph	NNE 6-25 mph	NE 6-24 mph	NE 6-24 mph	NNE 4-21 mph	NNE 5-23 mph
					UV: 6 High		UV: 6 High

Tonight	Mostly cloudy to cloudy in the evening, becoming dense overcast after midnight. Patchy light fog. Rain likely. Precipitation showery or intermittent. Warm. Low 71°. Wind north-northeast around 6 mph, gusting to 20 mph, in the evening, becoming 3 mph after midnight. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Monday	Cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. A chance of rain. Precipitation showery or intermittent. High 77°. Wind north-northeast around 4 mph, gusting to 23 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Monday night	Mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Low 66°. Wind north-northeast around 5 mph, gusting to 22 mph.
Tuesday	Cloudy in the morning, becoming mostly cloudy in the afternoon. High 75°. Wind north-northeast around 6 mph, gusting to 25 mph.
Tuesday night	Mostly cloudy to cloudy in the evening, becoming partly to mostly cloudy after midnight. Low 57°. Wind northeast around 6 mph, gusting to 24 mph.
Wednesday	Partly to mostly sunny in the morning, becoming mostly sunny in the afternoon. Patchy light fog in the morning. High 74°. UV index up to 6. Wind northeast around 6 mph, gusting to 24 mph.
Wednesday night	Fair in the evening, becoming fair to partly cloudy after midnight. Low 53°. Wind north-northeast around 4 mph, gusting to 21 mph.
Thursday	Partly to mostly sunny in the morning, becoming mostly cloudy in the afternoon. Patchy light fog in the morning. High 76°. UV index up to 6. Wind north-northeast around 5 mph, gusting to 23 mph.
Thursday night	Partly to mostly cloudy in the evening, becoming fair after midnight. Low 54°. Wind north-northeast around 4 mph, gusting to 18 mph.
Friday	Partly cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. A slight chance of rain. High 73°. Wind east-northeast around 5 mph, gusting to 19 mph. Chance of precipitation 20 percent. Precipitation mostly less than a tenth of an inch.
Friday night	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Low 56°. Wind east-northeast around 4 mph, gusting to 16 mph.
Saturday	Mostly cloudy. High 76°. Wind east-southeast around 6 mph, gusting to 23 mph.
Saturday night	Cloudy in the evening, becoming mostly cloudy to cloudy after midnight. Low 58°. Wind east-southeast around 4 mph, gusting to 20 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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