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, 20-Mar-2026 05:00 am

Today Mostly Sunny	Tonight Partly Cloudy	Saturday Sunny	Saturday night Partly Cloudy	Sunday Partly Cloudy	Sunday night Partly Cloudy	Monday Sunny	Monday night Partly Cloudy

High: 87°	Low: 46°	High: 82°	Low: 51°	High: 84°	Low: 38°	High: 60°	Low: 39°

WSW 6-25 mph	NW→NE 3-20 mph	ESE→SSW 3-21 mph	SSW 7 mph	SSW→WNW 9-28 mph	N 13-29→10-23 mph	N 7-26 mph	ENE→SE 5-19 mph
UV: 5 Medium		UV: 6 High		UV: 5 Medium		UV: 5 Medium

Today	Sunny in the morning, becoming mostly sunny in the afternoon. Near record warmth. High 87°. UV index up to 5. Wind west-southwest around 6 mph, gusting to 25 mph.
Tonight	Partly cloudy in the evening, becoming fair after midnight. Low 46°. Wind northwest around 3 mph, gusting to 20 mph, in the evening, becoming northeast after midnight.
Saturday	Sunny. Unusually hot. High 82°. UV index up to 6. Wind east-southeast around 3 mph, gusting to 21 mph, in the morning, becoming south-southwest in the afternoon.
Saturday night	Clear in the evening, becoming fair to partly cloudy after midnight. Low 51°. Wind south-southwest around 7 mph.
Sunday	Mostly sunny in the morning, becoming partly cloudy in the afternoon. Exceptionally hot. High 84°. UV index up to 5. Wind south-southwest around 9 mph, gusting to 28 mph, in the morning, becoming west-northwest in the afternoon.
Sunday night	Partly cloudy in the evening, becoming mostly clear after midnight. Breezy. Low 38°. Wind north around 13 mph, gusting to 29 mph, in the evening, becoming 10 mph, gusting to 23 mph, after midnight.
Monday	Sunny. High 60°. UV index up to 5. Wind north around 7 mph, gusting to 26 mph.
Monday night	Partly cloudy in the evening, becoming partly to mostly cloudy after midnight. Low 39°. Wind east-northeast around 5 mph, gusting to 19 mph, in the evening, becoming southeast after midnight.
Tuesday	Partly to mostly cloudy in the morning, becoming mostly cloudy in the afternoon. A chance of rain in the afternoon. High 64°. UV index up to 5. Wind south-southeast around 7 mph, gusting to 25 mph. Chance of precipitation 40 percent. Precipitation mostly less than a tenth of an inch.
Tuesday night	Partly to mostly cloudy in the evening, becoming partly cloudy after midnight. Patchy light fog after midnight. A chance of rain. Low 40°. Wind southwest around 5 mph, gusting to 16 mph, in the evening, becoming north after midnight. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch.
Wednesday	Partly cloudy. Patchy light fog in the morning. High 63°. UV index up to 5. Wind northeast around 5 mph, gusting to 22 mph, in the morning, becoming east in the afternoon.
Wednesday night	Clear. Low 43°. Wind south-southeast around 6 mph, gusting to 20 mph, in the evening, becoming 10 mph after midnight.
Thursday	Mostly sunny in the morning, becoming cloudy in the afternoon. Breezy and unusually hot. High 82°. UV index up to 4. Wind southwest around 14 mph, gusting to 30 mph, in the morning, becoming north-northwest in the afternoon.
Thursday night	Partly cloudy in the evening, becoming clear after midnight. Breezy. Low 38°. Wind chill ranging from 31 to 60. Wind north around 11 mph, gusting to 28 mph.

WXSIM forecast formatting script by Saratoga-Weather.org.

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