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: Friday, 25-Sep-2026 04:00 pm

Tonight Fog	Saturday Fog a.m.	Saturday night Mostly Cloudy	Sunday Fog a.m.	Sunday night Fog late	Monday Fog a.m.	Monday night Partly Cloudy	Tuesday Mostly Cloudy

Low: 58°	High: 74°	Low: 56°	High: 77°	Low: 55°	High: 77°	Low: 53°	High: 81°

E 4-21 mph	E 4-21 mph	E 3-17 mph	ESE 3-22 mph	ENE 2 mph	ENE 3-20 mph	E→SE 3 mph	SSE 6-20 mph
	UV: 4 Medium		UV: 5 Medium		UV: 5 Medium		UV: 5 Medium

Tonight	Mostly cloudy in the evening, becoming partly to mostly cloudy after midnight. Patchy light fog. Low 58°. Wind east around 4 mph, gusting to 21 mph.
Saturday	Mostly cloudy to cloudy. Patchy light fog in the morning. High 74°. UV index up to 4. Wind east around 4 mph, gusting to 21 mph.
Saturday night	Mostly cloudy to cloudy in the evening, becoming partly to mostly cloudy after midnight. Low 56°. Wind east around 3 mph, gusting to 17 mph.
Sunday	Partly cloudy. Patchy light fog in the morning. Warm. High 77°. UV index up to 5. Wind east-southeast around 3 mph, gusting to 22 mph.
Sunday night	Mostly clear in the evening, becoming partly cloudy after midnight. Patchy light fog after midnight. Low 55°. Wind east-northeast around 2 mph.
Monday	Partly to mostly sunny. Patchy light fog in the morning. High 77°. UV index up to 5. Wind east-northeast around 3 mph, gusting to 20 mph.
Monday night	Clear in the evening, becoming partly cloudy after midnight. Low 53°. Wind east around 3 mph in the evening, becoming southeast after midnight.
Tuesday	Partly to mostly sunny in the morning, becoming partly to mostly cloudy in the afternoon. Warm. High 81°. UV index up to 5. Wind south-southeast around 6 mph, gusting to 20 mph.
Tuesday night	Mostly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. A chance of rain. Low 64°. Wind south around 5 mph, gusting to 15 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Wednesday	Dense overcast. Rain likely. Precipitation showery or intermittent. High 74°. Wind south around 4 mph, gusting to 16 mph. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Wednesday night	Dense overcast in the evening, becoming cloudy after midnight. Patchy light fog. A chance of rain in the evening, then a slight chance of rain after midnight. Precipitation showery or intermittent. Warm. Low 69°. Wind south around 5 mph. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch.
Thursday	Dense overcast in the morning, becoming cloudy in the afternoon. Rain likely. Scattered thundershowers possible. Warm. High 79°. Wind south around 7 mph, gusting to 19 mph, in the morning, becoming 12 mph, gusting to 23 mph, in the afternoon. Chance of precipitation 60 percent. Precipitation mostly less than a quarter of an inch.
Thursday night	Cloudy in the evening, becoming partly 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. Precipitation showery or intermittent. Warm. Low 70°. Wind south around 8 mph, gusting to 21 mph. Chance of precipitation 50 percent. Precipitation mostly around a tenth of an inch.

WXSIM forecast formatting script by Saratoga-Weather.org.

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