Areas of Dangerous Heat and Heavy Rain with Possible Flooding into this Weekend

Hot temperatures and high humidity are forecast to continue across much of northeast Texas into the mid-Mississippi Valley into this weekend with heat advisories in effect. Heavy to excessive rainfall occurring at times through Saturday could bring areas of flooding across parts of the central Plains into the upper Midwest/Great Lakes, and Four Corners states. Read More >

Hazardous Weather Conditions

Heat Advisory until September 19, 08:00 PM CDT

Current conditions at

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

Lat: 38.66°NLon: 90.66°WElev: 463ft.

Fair

83°F

28°C

Humidity	67%
Wind Speed	S 5 mph
Barometer	30.19 in (1021.3 mb)
Dewpoint	71°F (22°C)
Visibility	10.00 mi
Heat Index	88°F (31°C)
Last update	16 Sep 6:54 pm CDT

More Information:

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

Extended Forecast for

O'Fallon MO

Heat Advisory September 16, 07:55pm until September 19, 08:00pm

Click here for hazard details and duration

Heat Advisory

Heat Advisory September 16, 07:55pm until September 19, 08:00pm
NOW until 8:00pm Sat
Heat Advisory
Tonight
Low: 75 °F
Slight Chance
T-storms then
Mostly Clear
Thursday
High: 96 °F
Sunny
Thursday Night
Low: 73 °F
Mostly Clear
Friday
High: 94 °F
Sunny
Friday Night
Low: 74 °F
Mostly Clear
Saturday
High: 95 °F
Mostly Sunny
Saturday Night
Low: 72 °F
Partly Cloudy
then Chance
Showers
Sunday
High: 90 °F
Chance
Showers

Detailed Forecast

Tonight

A 20 percent chance of showers and thunderstorms before 9pm. Cloudy during the early evening, then gradual clearing, with a low around 75. Light south wind.

Thursday

Sunny, with a high near 96. Heat index values as high as 106. Calm wind becoming southwest 5 to 7 mph in the morning.

Thursday Night

Mostly clear, with a low around 73. South wind around 5 mph becoming calm in the evening.

Friday

Sunny, with a high near 94. Heat index values as high as 103. Light and variable wind.

Friday Night

Mostly clear, with a low around 74. Calm wind becoming south around 5 mph after midnight.

Saturday

Mostly sunny, with a high near 95.

Saturday Night

A 40 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 72.

Sunday

A chance of showers, with thunderstorms also possible after 1pm. Partly sunny, with a high near 90. Chance of precipitation is 30%.

Sunday Night

A slight chance of showers and thunderstorms, then a chance of showers after 1am. Mostly cloudy, with a low around 67. Chance of precipitation is 30%.

Monday

A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 85. Chance of precipitation is 30%.

Monday Night

A 30 percent chance of showers. Mostly cloudy, with a low around 64.

Tuesday

A 20 percent chance of showers. Partly sunny, with a high near 80.

Tuesday Night

A 20 percent chance of showers. Partly cloudy, with a low around 62.

Wednesday

Mostly sunny, with a high near 81.