National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

Southern Illinois Airport (KMDH)

Lat: 37.78°NLon: 89.25°WElev: 400ft.

Fair

78°F

26°C

Humidity 60%
Wind Speed S 12 mph
Barometer 29.90 in (1012.2 mb)
Dewpoint 63°F (17°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 14 Apr 7:52 pm CDT
Extended Forecast for

Grand Tower IL

  • Tonight

    Tonight: A slight chance of showers and thunderstorms before 4am, then a slight chance of showers and thunderstorms after 5am. Partly cloudy, with a low around 69. South southwest wind 10 to 14 mph, with gusts as high as 23 mph. Chance of precipitation is 20%.

    Low: 69 °F

    Partly Cloudy
    then Slight
    Chance
    T-storms

  • Wednesday

    Wednesday: A slight chance of showers before 1pm, then a slight chance of showers and thunderstorms between 1pm and 5pm. Partly sunny, with a high near 84. South southwest wind 10 to 16 mph, with gusts as high as 26 mph. Chance of precipitation is 20%.

    High: 84 °F

    Slight Chance
    Showers then
    Slight Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 64. South southwest wind 9 to 13 mph, with gusts as high as 20 mph. Chance of precipitation is 70%.

    Low: 64 °F

    Chance
    Showers then
    Showers
    Likely

  • Thursday

    Thursday: Showers and possibly a thunderstorm before 10am, then showers between 10am and 1pm, then showers likely and possibly a thunderstorm after 1pm. High near 83. Southwest wind 9 to 11 mph, with gusts as high as 18 mph. Chance of precipitation is 80%.

    High: 83 °F

    Showers

  • Thursday Night

    Thursday Night: A chance of thunderstorms before 7pm. Mostly clear, with a low around 62. South southwest wind 3 to 7 mph. Chance of precipitation is 30%.

    Low: 62 °F

    Chance
    T-storms then
    Mostly Clear

  • Friday

    Friday: A 30 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 87. South wind 5 to 11 mph, with gusts as high as 21 mph.

    High: 87 °F

    Mostly Sunny
    then Chance
    T-storms

  • Friday Night

    Friday Night: A 40 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 62. South wind 10 to 13 mph, with gusts as high as 21 mph.

    Low: 62 °F

    Slight Chance
    T-storms then
    Chance
    Showers

  • Saturday

    Saturday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 76. South southwest wind 11 to 15 mph becoming west northwest in the afternoon. Winds could gust as high as 23 mph.

    High: 76 °F

    Chance
    T-storms then
    Showers
    Likely

  • Saturday Night

    Saturday Night: A chance of showers, mainly before 1am. Partly cloudy, with a low around 42. West northwest wind 8 to 11 mph, with gusts as high as 18 mph.

    Low: 42 °F

    Chance
    Showers

Detailed Forecast

Tonight
A slight chance of showers and thunderstorms before 4am, then a slight chance of showers and thunderstorms after 5am. Partly cloudy, with a low around 69. South southwest wind 10 to 14 mph, with gusts as high as 23 mph. Chance of precipitation is 20%.
Wednesday
A slight chance of showers before 1pm, then a slight chance of showers and thunderstorms between 1pm and 5pm. Partly sunny, with a high near 84. South southwest wind 10 to 16 mph, with gusts as high as 26 mph. Chance of precipitation is 20%.
Wednesday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 64. South southwest wind 9 to 13 mph, with gusts as high as 20 mph. Chance of precipitation is 70%.
Thursday
Showers and possibly a thunderstorm before 10am, then showers between 10am and 1pm, then showers likely and possibly a thunderstorm after 1pm. High near 83. Southwest wind 9 to 11 mph, with gusts as high as 18 mph. Chance of precipitation is 80%.
Thursday Night
A chance of thunderstorms before 7pm. Mostly clear, with a low around 62. South southwest wind 3 to 7 mph. Chance of precipitation is 30%.
Friday
A 30 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 87. South wind 5 to 11 mph, with gusts as high as 21 mph.
Friday Night
A 40 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 62. South wind 10 to 13 mph, with gusts as high as 21 mph.
Saturday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 76. South southwest wind 11 to 15 mph becoming west northwest in the afternoon. Winds could gust as high as 23 mph.
Saturday Night
A chance of showers, mainly before 1am. Partly cloudy, with a low around 42. West northwest wind 8 to 11 mph, with gusts as high as 18 mph.
Sunday
Sunny, with a high near 65. Northwest wind 7 to 11 mph, with gusts as high as 18 mph.
Sunday Night
Clear, with a low around 40. North northwest wind 5 to 7 mph becoming light and variable after midnight.
Monday
Sunny, with a high near 69. South wind 5 to 7 mph.
Monday Night
Mostly clear, with a low around 46. South wind around 6 mph.
Tuesday
Sunny, with a high near 74. South wind 6 to 10 mph, with gusts as high as 18 mph.
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ABOUT THIS FORECAST

 
Point Forecast:
Grand Tower IL
 37.64°N 89.52°W
Last Update:
6:31 pm CDT Apr 14, 2026
Forecast Valid:
8pm CDT Apr 14, 2026-6pm CDT Apr 21, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation