Severe Thunderstorms in the Midwest and Arizona; Heat Continues in the Southeast and Southwest

Thunderstorms, some severe, may lead to scattered instances of flash flooding across the Midwest and Ohio Valley and southern Arizona. The threat will shift to the Mid-Atlantic coast on Thursday. Dangerous heat persists in the South and Southeast while building into the Southwest. Overnight lows will be so warm that little-to-no relief from the scorching daytime highs will be available. Read More >

Current conditions at

St. Louis Downtown Airport (KCPS)

Lat: 38.56°NLon: 90.15°WElev: 410ft.

Overcast

76°F

24°C

Humidity 94%
Wind Speed Calm
Barometer 29.91 in (1012.3 mb)
Dewpoint 74°F (23°C)
Visibility 10.00 mi
Heat Index76°F (24°C)
Last update 19 Aug 8:53 pm CDT
Extended Forecast for

Caseyville IL

  • Tonight

    Tonight: A 30 percent chance of showers and thunderstorms, mainly before 1am.  Patchy fog after 2am.  Otherwise, mostly cloudy, with a low around 70. Light northeast wind.

    Low: 70 °F

    Chance
    T-storms and
    Patchy Fog

  • Thursday

    Thursday: Patchy fog before 9am.  Otherwise, partly sunny, with a high near 85. Calm wind becoming northeast around 6 mph in the morning.

    High: 85 °F

    Patchy Fog
    then Partly
    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 67. Northeast wind around 5 mph becoming calm  in the evening.

    Low: 67 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 88. Light and variable wind.

    High: 88 °F

    Sunny

  • Friday Night

    Friday Night: A 20 percent chance of showers and thunderstorms after 1am.  Mostly clear, with a low around 69. Light and variable wind.

    Low: 69 °F

    Mostly Clear
    then Slight
    Chance
    T-storms

  • Saturday

    Saturday: Mostly sunny, with a high near 86.

    High: 86 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 66.

    Low: 66 °F

    Mostly Clear

  • Sunday

    Sunday: Mostly sunny, with a high near 85.

    High: 85 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: A 20 percent chance of showers.  Mostly cloudy, with a low around 65.

    Low: 65 °F

    Slight Chance
    Showers

Detailed Forecast

Tonight
A 30 percent chance of showers and thunderstorms, mainly before 1am. Patchy fog after 2am. Otherwise, mostly cloudy, with a low around 70. Light northeast wind.
Thursday
Patchy fog before 9am. Otherwise, partly sunny, with a high near 85. Calm wind becoming northeast around 6 mph in the morning.
Thursday Night
Mostly clear, with a low around 67. Northeast wind around 5 mph becoming calm in the evening.
Friday
Sunny, with a high near 88. Light and variable wind.
Friday Night
A 20 percent chance of showers and thunderstorms after 1am. Mostly clear, with a low around 69. Light and variable wind.
Saturday
Mostly sunny, with a high near 86.
Saturday Night
Mostly clear, with a low around 66.
Sunday
Mostly sunny, with a high near 85.
Sunday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 65.
Monday
Partly sunny, with a high near 85.
Monday Night
Partly cloudy, with a low around 67.
Tuesday
Mostly sunny, with a high near 88.
Tuesday Night
Partly cloudy, with a low around 69.
Wednesday
Mostly sunny, with a high near 90.
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ABOUT THIS FORECAST

 
Point Forecast:
Caseyville IL
 38.66°N 90.06°W (Elev. 433 ft)
6:01 pm CDT Aug 19, 2026
9pm CDT Aug 19, 2026-6pm CDT Aug 26, 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