Thunderstorms and Heavy Rain in the Mid-South; Heat Continues in the Southeast and Southwest

Severe thunderstorms and heavy rain are expected across portions of the mid-Mississippi Valley into the Ohio Valley and portions of Arizona. Dangerous heat persists in the South and Southeast while building into the Southwest. Overnight lows will be so warm that, when combined with oppressive dew points, little-to-no relief from the scorching daytime highs will be available. Read More >

Current conditions at

St. Louis Regional Airport (KALN)

Lat: 38.89°NLon: 90.03°WElev: 518ft.

Light Rain

N/A

Humidity NA
Wind Speed NW 3 mph
Barometer 29.95 in
Dewpoint N/A
Visibility 10.00 mi
Last update 19 Aug 3:55 am CDT
Extended Forecast for

3 Miles S Donnellson IL

  • Overnight

    Overnight: Showers and thunderstorms.  Low around 67. Calm wind.  Chance of precipitation is 80%.

    Low: 67 °F

    T-storms

  • Wednesday

    Wednesday: Showers and thunderstorms likely, mainly before 1pm.  Cloudy, with a high near 79. Light southwest wind.  Chance of precipitation is 70%.

    High: 79 °F

    T-storms
    Likely then
    Scattered
    T-storms

  • Wednesday Night

    Wednesday Night: Scattered showers and thunderstorms, mainly before midnight.  Mostly cloudy, with a low around 66. Calm wind.  Chance of precipitation is 30%.

    Low: 66 °F

    Scattered
    T-storms

  • Thursday

    Thursday: Mostly sunny, with a high near 82. Calm wind becoming northeast around 5 mph.

    High: 82 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 63. Calm wind.

    Low: 63 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 84.

    High: 84 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 65.

    Low: 65 °F

    Mostly Clear

  • Saturday

    Saturday: A 20 percent chance of showers and thunderstorms.  Mostly sunny, with a high near 84.

    High: 84 °F

    Slight Chance
    T-storms

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 63.

    Low: 63 °F

    Mostly Clear

Detailed Forecast

Overnight
Showers and thunderstorms. Low around 67. Calm wind. Chance of precipitation is 80%.
Wednesday
Showers and thunderstorms likely, mainly before 1pm. Cloudy, with a high near 79. Light southwest wind. Chance of precipitation is 70%.
Wednesday Night
Scattered showers and thunderstorms, mainly before midnight. Mostly cloudy, with a low around 66. Calm wind. Chance of precipitation is 30%.
Thursday
Mostly sunny, with a high near 82. Calm wind becoming northeast around 5 mph.
Thursday Night
Mostly clear, with a low around 63. Calm wind.
Friday
Sunny, with a high near 84.
Friday Night
Mostly clear, with a low around 65.
Saturday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 84.
Saturday Night
Mostly clear, with a low around 63.
Sunday
Mostly sunny, with a high near 81.
Sunday Night
A 20 percent chance of showers. Partly cloudy, with a low around 62.
Monday
Mostly sunny, with a high near 81.
Monday Night
Partly cloudy, with a low around 64.
Tuesday
Mostly sunny, with a high near 84.
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ABOUT THIS FORECAST

 
Point Forecast:
3 Miles S Donnellson IL
 38.97°N 89.48°W (Elev. 600 ft)
3:26 am CDT Aug 19, 2026
4am CDT Aug 19, 2026-6pm CDT Aug 25, 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