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 05:00 am

Today Mostly Cloudy	Tonight Partly Cloudy	Monday Fog a.m.	Monday night Partly Cloudy	Tuesday Partly Cloudy	Tuesday night Partly Cloudy	Wednesday Partly Cloudy	Wednesday night Partly Cloudy
<.1 in.
High: 75°	Low: 54°	High: 77°	Low: 53°	High: 82°	Low: 57°	High: 88°	Low: 62°

ENE 3-21 mph	ENE 2-17 mph	ENE 3-22 mph	ENE→SE 2 mph	SSE 5-23 mph	SSE 6 mph	SSE 7-22 mph	SSE 6 mph
UV: 4 Medium		UV: 6 High		UV: 6 High		UV: 6 High

Today	Mostly cloudy to cloudy in the morning, becoming mostly cloudy in the afternoon. A chance of rain. High 75°. UV index up to 4. Wind east-northeast around 3 mph, gusting to 21 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Tonight	Partly cloudy. Low 54°. Wind east-northeast around 2 mph, gusting to 17 mph.
Monday	Partly to mostly sunny. Patchy light fog in the morning. Warm. High 77°. UV index up to 6. Wind east-northeast around 3 mph, gusting to 22 mph.
Monday night	Fair to partly cloudy. Low 53°. Wind east-northeast around 2 mph in the evening, becoming southeast after midnight.
Tuesday	Mostly sunny in the morning, becoming partly cloudy in the afternoon. Warm. High 82°. UV index up to 6. Wind south-southeast around 5 mph, gusting to 23 mph.
Tuesday night	Partly cloudy. Low 57°. Wind south-southeast around 6 mph.
Wednesday	Partly to mostly cloudy in the morning, becoming partly cloudy in the afternoon. Unusually hot. High 88°. UV index up to 6. Wind south-southeast around 7 mph, gusting to 22 mph.
Wednesday night	Partly cloudy. Low 62°. Wind south-southeast around 6 mph.
Thursday	Partly to mostly cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. A chance of rain. Precipitation showery or intermittent. Warm. High 83°. UV index up to 4. Wind south-southwest around 5 mph, gusting to 18 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Thursday night	Mostly cloudy to cloudy in the evening, becoming dense overcast after midnight. Patchy light fog after midnight. A chance of rain. Precipitation showery or intermittent. Low 63°. Wind north around 6 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Friday	Dense overcast. Patchy light fog in the afternoon. Rain likely. High 65°, but temperatures falling in the afternoon. Wind north around 8 mph, gusting to 18 mph. Chance of precipitation 70 percent. Precipitation mostly between a quarter and half an inch.
Friday night	Dense overcast. A chance of rain. Low 58°. Wind northeast around 4 mph, gusting to 17 mph, in the evening, becoming east after midnight. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch.
Saturday	Dense overcast. A chance of rain. High 65°. Wind east around 5 mph, gusting to 19 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Saturday night	Dense overcast. Patchy light fog after midnight. A chance of rain in the evening, then rain likely after midnight. Low 57°. Wind east-southeast around 3 mph in the evening, becoming south-southeast after midnight. Chance of precipitation 80 percent. Precipitation mostly between half an inch and one inch.

WXSIM forecast formatting script by Saratoga-Weather.org.

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