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Hawaii braces for Tropical Storm Lala, rare landfall possible. Click for the forecast.

O'Fallon, MO

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O'Fallon, MO Weather

Today WinterCast Local {stormName} Tracker Hourly 10-Day Radar MinuteCast® Monthly Air Quality Health & Activities

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Hourly

10-Day Radar MinuteCast® Monthly Air Quality Health & Activities

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5 PM

94°

RealFeel® 104°

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.

16%

Partly sunny

Extreme Heat Warning

12:00 PM Sunday - 9:00 PM Sunday

RealFeel Shade™100°

Heat Index104°

WindS 7 mph

Air QualityFair

Max UV Index2.8 (Moderate)

Wind Gusts8 mph

Humidity53%

Indoor Humidity53% (Extremely Humid)

Dew Point74° F

AccuLumen Brightness Index™8 (Bright)

Cloud Cover46%

Visibility10 mi

Cloud Ceiling30000 ft

6 PM

92°

RealFeel® 101°

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.

16%

Partly sunny

Extreme Heat Warning

12:00 PM Sunday - 9:00 PM Sunday

RealFeel Shade™98°

Heat Index102°

WindSSE 7 mph

Air QualityFair

Max UV Index1.7 (Low)

Wind Gusts8 mph

Humidity56%

Indoor Humidity56% (Extremely Humid)

Dew Point74° F

AccuLumen Brightness Index™8 (Bright)

Cloud Cover46%

Visibility10 mi

Cloud Ceiling30000 ft

7 PM

90°

RealFeel® 101°

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.

11%

Partly sunny

Extreme Heat Warning

12:00 PM Sunday - 9:00 PM Sunday

RealFeel Shade™101°

Heat Index102°

WindSE 6 mph

Air QualityFair

Max UV Index0.7 (Low)

Wind Gusts7 mph

Humidity64%

Indoor Humidity64% (Extremely Humid)

Dew Point76° F

AccuLumen Brightness Index™4 (Dull)

Cloud Cover46%

Visibility10 mi

Cloud Ceiling30000 ft

8 PM

88°

RealFeel® 99°

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.

0%

Mostly clear

Extreme Heat Warning

12:00 PM Sunday - 9:00 PM Sunday

Heat Index100°

WindESE 7 mph

Air QualityFair

Wind Gusts8 mph

Humidity71%

Indoor Humidity71% (Dangerously Humid)

Dew Point78° F

AccuLumen Brightness Index™0 (Dark)

Cloud Cover19%

Visibility10 mi

Cloud Ceiling30000 ft

9 PM

85°

RealFeel® 95°

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.

0%

Mostly clear

Extreme Heat Warning

12:00 PM Sunday - 9:00 PM Sunday

Heat Index95°

WindESE 7 mph

Air QualityFair

Wind Gusts7 mph

Humidity77%

Indoor Humidity77% (Extremely Humid)

Dew Point77° F

AccuLumen Brightness Index™0 (Dark)

Cloud Cover13%

Visibility10 mi

Cloud Ceiling30000 ft

10 PM

83°

RealFeel® 92°

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.

1%

Mostly clear

Extreme Heat Warning

12:00 PM Sunday - 9:00 PM Sunday

Heat Index91°

WindSE 6 mph

Air QualityFair

Wind Gusts7 mph

Humidity81%

Indoor Humidity81% (Extremely Humid)

Dew Point76° F

AccuLumen Brightness Index™0 (Dark)

Cloud Cover15%

Visibility10 mi

Cloud Ceiling30000 ft

11 PM

81°

RealFeel® 89°

Very Warm

RealFeel Guide

Very Warm

82° to 89°

Older adults, infants, and those with sensitive medical conditions should minimize outdoor activity, especially in the sunshine.

2%

Partly cloudy

Extreme Heat Warning

12:00 PM Sunday - 9:00 PM Sunday

Heat Index87°

WindSE 6 mph

Air QualityFair

Wind Gusts7 mph

Humidity85%

Indoor Humidity85% (Extremely Humid)

Dew Point76° F

AccuLumen Brightness Index™0 (Dark)

Cloud Cover31%

Visibility10 mi

Cloud Ceiling30000 ft

Hourly Weather Forecast for O'Fallon

AccuWeather's hourly forecast for O'Fallon provides hour-by-hour temperatures, RealFeel® Temperature, and precipitation probability through the next 10 days. The current hour shows 94° with a RealFeel® of 104°, partly sunny with a 16% chance of precipitation. Each hourly forecast includes wind speed, humidity, air quality, UV index, and the AccuLumen Brightness Index™, AccuWeather's measure of perceived outdoor light intensity. Forecasts are generated by proprietary systems developed by AccuWeather meteorologists since 1962.

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