Severe Thunderstorms and Heavy Rain Across the Ohio Valley;

Severe thunderstorms with damaging wind gusts will be possible from the mid-Mississippi Valley into parts of the Ohio Valley and central Appalachians. Heavy rain associated with these storms may lead to considerable flash and urban flooding impacts across portions of the Ohio Valley. Mid-summer heat persists from the Central Plains to the Southeast. Read More >

Current conditions at

St. Louis Regional Airport (KALN)

Lat: 38.89°NLon: 90.03°WElev: 518ft.

Fair

93°F

34°C

Humidity 56%
Wind Speed SW 13 mph
Barometer 29.89 in
Dewpoint 75°F (24°C)
Visibility 10.00 mi
Heat Index105°F (41°C)
Last update 11 Aug 4:50 pm CDT
Extended Forecast for

3 Miles SSE Carlinville IL

Heat Advisory August 11, 04:57pm until August 12, 08:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 11, 04:57pm until August 12, 08:00pm

    NOW until 8:00pm Wed

    Heat Advisory

  • Tonight

    Low: 74 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Scattered showers and thunderstorms, mainly after 2pm.  Mostly sunny, with a high near 92. Heat index values as high as 103. South wind 5 to 7 mph becoming west in the afternoon.  Chance of precipitation is 30%.

    High: 92 °F

    Scattered
    T-storms

  • Wednesday Night

    Wednesday Night: Scattered showers and thunderstorms, mainly after 3am.  Partly cloudy, with a low around 71. Light south wind.  Chance of precipitation is 30%.

    Low: 71 °F

    Scattered
    T-storms

  • Thursday

    Thursday: Scattered showers and thunderstorms before 1pm.  Partly sunny, with a high near 91. Heat index values as high as 102. Light and variable wind becoming south around 5 mph in the morning.  Chance of precipitation is 30%.

    High: 91 °F

    Scattered
    T-storms then
    Chance
    Showers

  • Thursday Night

    Thursday Night: A 30 percent chance of showers and thunderstorms.  Mostly cloudy, with a low around 70. East wind around 5 mph.

    Low: 70 °F

    Chance
    T-storms

  • Friday

    Friday: Partly sunny, with a high near 90.

    High: 90 °F

    Partly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 71.

    Low: 71 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 94.

    High: 94 °F

    Mostly Sunny

Detailed Forecast

Tonight
Partly cloudy, with a low around 74. South wind 3 to 7 mph.
Wednesday
Scattered showers and thunderstorms, mainly after 2pm. Mostly sunny, with a high near 92. Heat index values as high as 103. South wind 5 to 7 mph becoming west in the afternoon. Chance of precipitation is 30%.
Wednesday Night
Scattered showers and thunderstorms, mainly after 3am. Partly cloudy, with a low around 71. Light south wind. Chance of precipitation is 30%.
Thursday
Scattered showers and thunderstorms before 1pm. Partly sunny, with a high near 91. Heat index values as high as 102. Light and variable wind becoming south around 5 mph in the morning. Chance of precipitation is 30%.
Thursday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 70. East wind around 5 mph.
Friday
Partly sunny, with a high near 90.
Friday Night
Partly cloudy, with a low around 71.
Saturday
Mostly sunny, with a high near 94.
Saturday Night
Mostly clear, with a low around 73.
Sunday
Mostly sunny, with a high near 93.
Sunday Night
Partly cloudy, with a low around 69.
Monday
A 20 percent chance of showers. Mostly sunny, with a high near 85.
Monday Night
Partly cloudy, with a low around 65.
Tuesday
Mostly sunny, with a high near 86.
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ABOUT THIS FORECAST

 
Point Forecast:
3 Miles SSE Carlinville IL
 39.25°N 89.86°W (Elev. 551 ft)
1:26 pm CDT Aug 11, 2026
4pm CDT Aug 11, 2026-6pm CDT Aug 18, 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