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, 27-Sep-2026 04:00 pm

Tonight Fog late	Monday Fog a.m.	Monday night Fog late	Tuesday Fog a.m.	Tuesday night Partly Cloudy	Wednesday Partly Cloudy	Wednesday night Partly Cloudy	Thursday Chance rain
							<.25 in.
Low: 55°	High: 76°	Low: 52°	High: 80°	Low: 55°	High: 84°	Low: 62°	High: 79°

NE 3-16 mph	NE 3-20 mph	NE→SE 2 mph	SSE 5-22 mph	SSE 5 mph	SSE 7-20 mph	S 6 mph	SSW 4 mph
	UV: 6 High		UV: 6 High		UV: 5 Medium

Tonight	Partly to mostly cloudy. Patchy light fog after midnight. Low 55°. Wind northeast around 3 mph, gusting to 16 mph.
Monday	Partly cloudy in the morning, becoming sunny in the afternoon. Patchy light fog in the morning. High 76°. UV index up to 6. Wind northeast around 3 mph, gusting to 20 mph.
Monday night	Clear. Patchy light fog after midnight. Low 52°. Wind northeast around 2 mph in the evening, becoming southeast after midnight.
Tuesday	Partly to mostly sunny in the morning, becoming mostly sunny in the afternoon. Patchy light fog in the morning. Warm. High 80°. UV index up to 6. Wind south-southeast around 5 mph, gusting to 22 mph.
Tuesday night	Partly cloudy in the evening, becoming fair to partly cloudy after midnight. Low 55°. Wind south-southeast around 5 mph.
Wednesday	Partly cloudy. Warm. High 84°. UV index up to 5. Wind south-southeast around 7 mph, gusting to 20 mph.
Wednesday night	Fair to partly cloudy in the evening, becoming partly to mostly cloudy after midnight. Low 62°. Wind south around 6 mph.
Thursday	Mostly cloudy to cloudy in the morning, becoming cloudy in the afternoon. A slight chance of rain in the morning, then a chance of rain in the afternoon. Precipitation showery or intermittent. Warm. High 79°. Wind south-southwest around 4 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Thursday night	Dense overcast. Light to moderate fog in the evening, then patchy light fog after midnight. Rain likely. Precipitation showery or intermittent. Low 63°. Wind north around 6 mph, gusting to 19 mph. Chance of precipitation 80 percent. Precipitation mostly between half an inch and one inch.
Friday	Cloudy in the morning, becoming partly to mostly sunny in the afternoon. A chance of rain in the morning, then a slight chance of rain in the afternoon. High 74°. UV index up to 7. Wind north around 8 mph, gusting to 25 mph. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch.
Friday night	Mostly clear. Patchy light fog after midnight. Low 52°. Wind north-northeast around 6 mph, gusting to 22 mph.
Saturday	Sunny. Light to moderate fog in the morning. High 69°. UV index up to 5. Wind northeast around 8 mph, gusting to 26 mph.
Saturday night	Partly cloudy in the evening, becoming mostly cloudy after midnight. Low 53°. Wind east-northeast around 5 mph, gusting to 19 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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