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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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May 18 - June 1

Mon 5/18

Mostly cloudy, heavy t-storms, not as warm; breezy in the morning, humid in the p.m.; thunderstorms can bring flash flooding and localized damaging wind gusts

Flood Watch

9:02 AM Monday - 7:00 PM Monday

RealFeel®79°

RealFeel Shade™74°

Max UV Index4.0 (Moderate)

WindSSW 12 mph

Hours of Precipitation5.5

Hours of Rain5.5

Tue 5/19

Cloudy and humid with a shower and t-storm; breezy in the morning, then not as warm in the afternoon; thunderstorms can bring localized damaging wind gusts

RealFeel®83°

RealFeel Shade™80°

Max UV Index3.0 (Moderate)

WindWSW 12 mph

Hours of Precipitation2

Hours of Rain2

Wed 5/20

Cooler and less humid with sun and areas of high clouds

RealFeel®70°

RealFeel Shade™65°

Max UV Index4.0 (Moderate)

WindNNE 8 mph

Thu 5/21

Times of clouds and sun

RealFeel®72°

RealFeel Shade™68°

Max UV Index5.0 (Moderate)

WindE 8 mph

Fri 5/22

Cloudy with a couple of showers and a thunderstorm

RealFeel®71°

RealFeel Shade™71°

Max UV Index2.0 (Low)

WindENE 6 mph

Hours of Precipitation3.5

Hours of Rain3.5

Sat 5/23

Mostly cloudy and warmer with a couple of showers possible

RealFeel®79°

RealFeel Shade™77°

Max UV Index5.0 (Moderate)

WindSW 6 mph

Sun 5/24

Variable cloudiness with a thunderstorm possible

RealFeel®84°

RealFeel Shade™78°

Max UV Index5.0 (Moderate)

WindNW 4 mph

Mon 5/25

Intervals of clouds and sun

RealFeel®83°

RealFeel Shade™78°

Max UV Index7.0 (High)

WindE 7 mph

Tue 5/26

Cloudy and humid; showers in the morning followed by a couple of showers and a thunderstorm in the afternoon

RealFeel®82°

RealFeel Shade™82°

Max UV Index3.0 (Moderate)

WindENE 7 mph

Hours of Precipitation4

Hours of Rain4

Wed 5/27

Cloudy and humid with periods of rain and a thunderstorm

RealFeel®88°

RealFeel Shade™83°

Max UV Index5.0 (Moderate)

WindESE 5 mph

Hours of Precipitation6

Hours of Rain6

Thu 5/28

Humid with occasional rain

RealFeel®88°

RealFeel Shade™84°

Max UV Index5.0 (Moderate)

WindSSE 8 mph

Hours of Precipitation2.5

Hours of Rain2.5

Fri 5/29

Considerable cloudiness with rain tapering off; humid

RealFeel®86°

RealFeel Shade™84°

Max UV Index3.0 (Moderate)

WindSSE 12 mph

Hours of Precipitation4

Hours of Rain4

Sat 5/30

Humid with rain

RealFeel®86°

RealFeel Shade™84°

Max UV Index3.0 (Moderate)

WindS 6 mph

Hours of Precipitation5

Hours of Rain5

Sun 5/31

Partly sunny and humid

RealFeel®92°

RealFeel Shade™83°

Max UV Index11.0 (Extreme)

WindWSW 6 mph

Mon 6/1

Humid with times of clouds and sun

RealFeel®95°

RealFeel Shade™90°

Max UV Index11.0 (Extreme)

WindWNW 8 mph

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World North America United States Missouri O'Fallon

Weather Near O'Fallon:

St. Charles, MO
St. Louis, MO
St. Peters, MO

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