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100-degree heat dome to set up shop over southern US. Get the forecast Chevron right

O Fallon, IL

84°F
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O Fallon, IL Weather
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Winter Center
Today Hourly Daily Radar MinuteCast Monthly Air Quality Health & Activities
Monday, August 25

Day

8/25
91°Hi
RealFeel® 102°
Very Hot
RealFeel Guide
Very Hot
101° to 107°
Caution advised. Danger of dehydration, heat stroke, heat exhaustion and heat cramps if outside for extended periods, and especially while doing strenuous activities.
LEARN MORE
RealFeel Shade™ 96°
Hot
RealFeel Guide
Hot
90° to 100°
Caution advised. Possible danger of dehydration, heat stroke, heat exhaustion and heat cramps if outside for extended periods, and especially while doing strenuous activities.
LEARN MORE
Humid with sunshine and a few clouds

Max UV Index8 (Very High)

WindNW 5 mph

Wind Gusts13 mph

Probability of Precipitation20%

Probability of Thunderstorms4%

Precipitation0.00 in

Cloud Cover28%

Night

8/25
68°Lo
RealFeel® 69°
Pleasant
RealFeel Guide
Pleasant
63° to 81°
Most consider this temperature range ideal.
LEARN MORE
Partly cloudy

WindNNE 6 mph

Wind Gusts13 mph

Probability of Precipitation25%

Probability of Thunderstorms6%

Precipitation0.00 in

Cloud Cover55%

Sun & Moon

13 hrs 18 mins
Rise 6:22 AM
Set 7:40 PM
Waxing Crescent
Rise 8:44 AM
Set 8:48 PM

Temperature History

8/25
High
Low
Forecast
91°
68°
Average
89°
64°
Last Year
94°
67°
Record
101°
2023
50°
1966

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Weather Near O Fallon:

  • O'Fallon, MO
  • St. Charles, MO
  • St. Louis, MO
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