Active Weather Pattern Expected From the Midwest to the Southern Plains; Dangerous Heat Likely in Southern Texas

A strong storm system will bring numerous to widespread severe thunderstorms across portions of the Midwest and Upper Great Lakes Tuesday. Tornadoes (a few strong), damaging winds and large hail are expected. Record high temperatures will be possible over southern Texas the next several days. This may lead to dangerous heat concerns especially for areas already without power. Read More >

Hazardous Weather Conditions

Hazardous Weather Outlook

Current conditions at

St. Louis, Spirit Of St. Louis Airport (KSUS)

Lat: 38.66°NLon: 90.66°WElev: 463ft.

Partly Cloudy

86°F

30°C

Humidity	51%
Wind Speed	S 16 G 28 mph
Barometer	29.71 in (1005.2 mb)
Dewpoint	66°F (19°C)
Visibility	10.00 mi
Heat Index	88°F (31°C)
Last update	21 May 12:54 pm CDT

More Information:

Local Forecast Office More Local Wx 3 Day History Hourly Weather Forecast

Extended Forecast for

O'Fallon MO

This Afternoon
High: 92 °F
Mostly Sunny
and Breezy
Tonight
Low: 61 °F
T-storms then
Chance
T-storms
Wednesday
High: 76 °F
Sunny then
Chance
T-storms
Wednesday Night
Low: 61 °F
Chance
T-storms
Thursday
High: 81 °F
Chance
T-storms
Thursday Night
Low: 64 °F
Chance
T-storms
Friday
High: 83 °F
Showers
Likely
Friday Night
Low: 65 °F
Chance
T-storms
Saturday
High: 83 °F
Slight Chance
T-storms then
Chance
Showers

Detailed Forecast

This Afternoon

Mostly sunny, with a high near 92. Breezy, with a south wind 18 to 21 mph, with gusts as high as 33 mph.

Tonight

Showers and thunderstorms, mainly before midnight. Low around 61. South wind 7 to 17 mph becoming northwest after midnight. Winds could gust as high as 31 mph. Chance of precipitation is 90%.

Wednesday

A slight chance of showers between noon and 1pm, then a chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 76. Northwest wind around 6 mph. Chance of precipitation is 40%.

Wednesday Night

A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 61. North wind around 5 mph becoming calm in the evening.

Thursday

A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 81. Calm wind becoming southeast around 5 mph in the afternoon.

Thursday Night

A 50 percent chance of showers and thunderstorms. Partly cloudy, with a low around 64.

Friday

Showers likely and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 83. Chance of precipitation is 60%.

Friday Night

A 50 percent chance of showers and thunderstorms. Partly cloudy, with a low around 65.

Saturday

A 40 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 83.

Saturday Night

Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 65. Chance of precipitation is 70%.

Sunday

Showers likely and possibly a thunderstorm. Partly sunny, with a high near 83. Chance of precipitation is 60%.

Sunday Night

A 50 percent chance of showers and thunderstorms. Partly cloudy, with a low around 63.

Memorial Day

A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 82.