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: Saturday, 04-Jul-2026 05:00 am

Today Thunder storm Hot!	Tonight Chance rain	Sunday Fog a.m.	Sunday night Fog late	Monday Fog a.m.	Monday night Fog late	Tuesday Fog a.m.	Tuesday night Fog late
.35 in.	.25 in.
High: 95°	Low: 76°	High: 90°	Low: 71°	High: 89°	Low: 68°	High: 89°	Low: 68°
Heat: 105°		Heat: 99°		Heat: 95°		Heat: 94°
WSW→WNW 4-24 mph	S→WNW 3 mph	NW 4-23 mph	N 3-20 mph	N 4-24 mph	NE 4-22 mph	NE 4-23 mph	NE→ESE 3-21 mph
UV: 8 Very High		UV: 9 Very High		UV: 9 Very High		UV: 9 Very High

Today	Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. Patchy light fog in the afternoon. A slight chance of rain in the morning, then rain likely in the afternoon. Scattered thundershowers possible. Hot. High 95°. Heat index up to 105°. UV index up to 8. Wind west-southwest around 4 mph, gusting to 24 mph, in the morning, becoming west-northwest in the afternoon. Chance of precipitation 60 percent. Precipitation mostly between a quarter and half an inch.
Tonight	Moderate fog. A chance of rain in the evening, then a slight chance of rain after midnight. Low 76°. Wind south around 3 mph in the evening, becoming west-northwest after midnight. Chance of precipitation 60 percent. Precipitation mostly around a quarter of an inch.
Sunday	Partly cloudy in the morning, becoming partly to mostly sunny in the afternoon. Light to moderate fog in the morning. Hot. High 90°. Heat index up to 99°. UV index up to 9. Wind northwest around 4 mph, gusting to 23 mph.
Sunday night	Fair in the evening, becoming mostly clear after midnight. Patchy light fog in the evening, then moderate fog after midnight. Low 71°. Wind north around 3 mph, gusting to 20 mph.
Monday	Partly to mostly sunny in the morning, becoming mostly sunny in the afternoon. Moderate fog in the morning. High 89°. Heat index up to 95°. UV index up to 9. Wind north around 4 mph, gusting to 24 mph.
Monday night	Fair to partly cloudy in the evening, becoming fair after midnight. Patchy light fog after midnight. Low 68°. Wind northeast around 4 mph, gusting to 22 mph.
Tuesday	Partly to mostly sunny. Patchy light fog in the morning. High 89°. Heat index up to 94°. UV index up to 9. Wind northeast around 4 mph, gusting to 23 mph.
Tuesday night	Mostly clear in the evening, becoming fair after midnight. Patchy light fog after midnight. Low 68°. Wind northeast around 3 mph, gusting to 21 mph, in the evening, becoming east-southeast after midnight.
Wednesday	Partly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. Patchy light fog in the morning. A slight chance of rain in the morning, then a chance of rain in the afternoon. High 90°. Heat index up to 95°. UV index up to 7. Wind southeast around 4 mph, gusting to 21 mph, in the morning, becoming south-southwest in the afternoon. Chance of precipitation 40 percent. Precipitation mostly around a tenth of an inch.
Wednesday night	Mostly cloudy. Light to moderate fog after midnight. A slight chance of rain in the evening, then a chance of rain after midnight. Precipitation showery or intermittent. Low 74°. Wind south-southeast around 3 mph in the evening, becoming southwest after midnight. Chance of precipitation 50 percent. Precipitation mostly around a tenth of an inch.
Thursday	Mostly cloudy in the morning, becoming partly to mostly cloudy in the afternoon. Patchy light fog in the morning. A chance of rain. Scattered thundershowers possible. Hot. High 91°. Heat index up to 100°. UV index up to 7. Wind southwest around 4 mph, gusting to 21 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Thursday night	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Light to moderate fog in the evening, then moderate to dense fog after midnight. A chance of rain in the evening, then rain likely after midnight. Scattered thundershowers possible. Low 73°. Wind southeast around 4 mph, gusting to 19 mph. Chance of precipitation 70 percent. Precipitation mostly around half an inch.
Friday	Mostly cloudy to cloudy in the morning, becoming mostly cloudy in the afternoon. Light to moderate fog in the morning. A chance of rain. Scattered thundershowers possible. High 88°. Heat index up to 94°. UV index up to 7. Wind south-southwest around 4 mph, gusting to 20 mph, in the morning, becoming southeast in the afternoon. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch.
Friday night	Fair to partly cloudy. Patchy light fog in the evening, then moderate fog after midnight. Low 73°. Wind southeast around 5 mph, gusting to 17 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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