Heavy Rainfall and Severe Thunderstorm Threats; Heat Risk Expands; Monitoring the Tropics

Flash flooding risks continue for portions of the Four Corners and Great Basin through today. Severe thunderstorms are outlooked from the eastern Great Lakes, southern New England into the mid-Atlantic through Tuesday. Heat risk increases and expands across the center of the nation and across the Ohio Valley and mid-Atlantic this week. Continue to closely monitor tropical development in the Gulf. Read More >

Current conditions at

St. Louis Regional Airport (KALN)

Lat: 38.89°NLon: 90.03°WElev: 518ft.

Fair

82°F

28°C

Humidity 55%
Wind Speed S 9 mph
Barometer 30.05 in
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 31 Aug 9:50 am CDT
Extended Forecast for

3 Miles NNW Pontoon Beach IL

Heat Advisory August 31, 12:00pm until September 4, 08:00pm
Click here for hazard details and duration
Heat Advisory
  • Today

    Today: Sunny and hot, with a high near 97. Heat index values as high as 101. Southwest wind around 9 mph.

    High: 97 °F

    Hot

  • Tonight

    Tonight: Clear, with a low around 74. South wind around 7 mph.

    Low: 74 °F

    Clear

  • Tuesday

    Tuesday: Sunny and hot, with a high near 100. Heat index values as high as 103. Light and variable wind becoming southwest 5 to 7 mph in the morning.

    High: 100 °F

    Hot

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 78. South wind around 7 mph.

    Low: 78 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny and hot, with a high near 100. Southwest wind 5 to 9 mph.

    High: 100 °F

    Hot

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 79.

    Low: 79 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny and hot, with a high near 100.

    High: 100 °F

    Hot

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 78.

    Low: 78 °F

    Mostly Clear

  • Friday

    Friday: A 20 percent chance of showers and thunderstorms after 1pm.  Sunny, with a high near 94.

    High: 94 °F

    Sunny then
    Slight Chance
    T-storms

Detailed Forecast

Today
Sunny and hot, with a high near 97. Heat index values as high as 101. Southwest wind around 9 mph.
Tonight
Clear, with a low around 74. South wind around 7 mph.
Tuesday
Sunny and hot, with a high near 100. Heat index values as high as 103. Light and variable wind becoming southwest 5 to 7 mph in the morning.
Tuesday Night
Mostly clear, with a low around 78. South wind around 7 mph.
Wednesday
Sunny and hot, with a high near 100. Southwest wind 5 to 9 mph.
Wednesday Night
Mostly clear, with a low around 79.
Thursday
Sunny and hot, with a high near 100.
Thursday Night
Mostly clear, with a low around 78.
Friday
A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 94.
Friday Night
Mostly clear, with a low around 74.
Saturday
A 20 percent chance of showers and thunderstorms. Sunny, with a high near 94.
Saturday Night
Mostly clear, with a low around 73.
Sunday
Sunny, with a high near 92.
Basemap Options
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ABOUT THIS FORECAST

 
Point Forecast:
3 Miles NNW Pontoon Beach IL
 38.77°N 90.08°W (Elev. 427 ft)
10:26 am CDT Aug 31, 2026
10am CDT Aug 31, 2026-6pm CDT Sep 6, 2026
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database