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 Lambert International Airport (KSTL)

Lat: 38.75°NLon: 90.37°WElev: 604ft.

Mostly Cloudy

75°F

24°C

Humidity 84%
Wind Speed SW 13 G 21 mph
Barometer 29.94 in (1012.8 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Last update 19 Aug 9:51 am CDT
Extended Forecast for

Saint Charles MO

  • Today

    Today: Scattered showers and thunderstorms, mainly before 1pm.  Mostly cloudy, with a high near 81. Light and variable wind.  Chance of precipitation is 30%.

    High: 81 °F

    Scattered
    Showers

  • Tonight

    Tonight: Scattered showers and thunderstorms, mainly before 10pm.  Mostly cloudy, with a low around 68. Light north wind.  Chance of precipitation is 30%.

    Low: 68 °F

    Scattered
    T-storms then
    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 84. Northeast wind 3 to 5 mph.

    High: 84 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 67. Light east wind.

    Low: 67 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 86. Light and variable wind.

    High: 86 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 69.

    Low: 69 °F

    Mostly Clear

  • Saturday

    Saturday: A 20 percent chance of showers and thunderstorms before 1pm.  Mostly sunny, with a high near 86.

    High: 86 °F

    Slight Chance
    T-storms

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 67.

    Low: 67 °F

    Mostly Clear

  • Sunday

    Sunday: Mostly sunny, with a high near 83.

    High: 83 °F

    Mostly Sunny

Detailed Forecast

Today
Scattered showers and thunderstorms, mainly before 1pm. Mostly cloudy, with a high near 81. Light and variable wind. Chance of precipitation is 30%.
Tonight
Scattered showers and thunderstorms, mainly before 10pm. Mostly cloudy, with a low around 68. Light north wind. Chance of precipitation is 30%.
Thursday
Mostly sunny, with a high near 84. Northeast wind 3 to 5 mph.
Thursday Night
Mostly clear, with a low around 67. Light east wind.
Friday
Sunny, with a high near 86. Light and variable wind.
Friday Night
Mostly clear, with a low around 69.
Saturday
A 20 percent chance of showers and thunderstorms before 1pm. Mostly sunny, with a high near 86.
Saturday Night
Mostly clear, with a low around 67.
Sunday
Mostly sunny, with a high near 83.
Sunday Night
A 20 percent chance of showers after 1am. Partly cloudy, with a low around 66.
Monday
Partly sunny, with a high near 84.
Monday Night
Partly cloudy, with a low around 68.
Tuesday
Mostly sunny, with a high near 87.
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ABOUT THIS FORECAST

 
Point Forecast:
Saint Charles MO
 38.81°N 90.54°W (Elev. 512 ft)
8:11 am CDT Aug 19, 2026
10am 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