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

Hazardous Weather Conditions

Current conditions at

Southern Illinois Airport (KMDH)

Lat: 37.78°NLon: 89.25°WElev: 400ft.

A Few Clouds

77°F

25°C

Humidity 77%
Wind Speed S 8 mph
Barometer 29.90 in (1012.0 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Heat Index79°F (26°C)
Last update 21 Jun 8:52 am CDT
Extended Forecast for

Grand Tower IL

  • Today

    Today: A 50 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 89. South wind 6 to 15 mph, with gusts as high as 26 mph.

    High: 89 °F

    Partly Sunny
    then Chance
    T-storms

  • Tonight

    Tonight: Showers and thunderstorms, mainly before 2am, then showers likely and possibly a thunderstorm after 4am. Low around 68. South wind 7 to 14 mph, with gusts as high as 22 mph. Chance of precipitation is 90%.

    Low: 68 °F

    T-storms then
    Showers
    Likely

  • Monday

    Monday: A chance of showers and thunderstorms before 11am, then a slight chance of showers between 11am and noon. Mostly cloudy, with a high near 80. Northwest wind around 8 mph. Chance of precipitation is 40%.

    High: 80 °F

    Chance
    Showers then
    Mostly Cloudy

  • Monday Night

    Monday Night: Partly cloudy, with a low around 62. North wind 5 to 7 mph becoming calm in the evening.

    Low: 62 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 83. Calm wind.

    High: 83 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 63. Light north wind.

    Low: 63 °F

    Mostly Clear

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 85. Calm wind.

    High: 85 °F

    Sunny then
    Slight Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A slight chance of showers and thunderstorms. Partly cloudy, with a low around 66. Calm wind.

    Low: 66 °F

    Slight Chance
    T-storms

  • Thursday

    Thursday: A chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 86. Calm wind becoming west northwest around 5 mph in the afternoon.

    High: 86 °F

    Mostly Sunny
    then Chance
    T-storms

Detailed Forecast

Today
A 50 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 89. South wind 6 to 15 mph, with gusts as high as 26 mph.
Tonight
Showers and thunderstorms, mainly before 2am, then showers likely and possibly a thunderstorm after 4am. Low around 68. South wind 7 to 14 mph, with gusts as high as 22 mph. Chance of precipitation is 90%.
Monday
A chance of showers and thunderstorms before 11am, then a slight chance of showers between 11am and noon. Mostly cloudy, with a high near 80. Northwest wind around 8 mph. Chance of precipitation is 40%.
Monday Night
Partly cloudy, with a low around 62. North wind 5 to 7 mph becoming calm in the evening.
Tuesday
Mostly sunny, with a high near 83. Calm wind.
Tuesday Night
Mostly clear, with a low around 63. Light north wind.
Wednesday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 85. Calm wind.
Wednesday Night
A slight chance of showers and thunderstorms. Partly cloudy, with a low around 66. Calm wind.
Thursday
A chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 86. Calm wind becoming west northwest around 5 mph in the afternoon.
Thursday Night
A slight chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 65. Light and variable wind.
Friday
A chance of showers and thunderstorms. Mostly sunny, with a high near 87. Light and variable wind.
Friday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 69. South wind around 6 mph becoming calm in the evening.
Saturday
A chance of showers and thunderstorms. Partly sunny, with a high near 88. South southwest wind 5 to 13 mph, with gusts as high as 21 mph.
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ABOUT THIS FORECAST

 
Point Forecast:
Grand Tower IL
 37.64°N 89.52°W
Last Update:
8:51 am CDT Jun 21, 2026
Forecast Valid:
9am CDT Jun 21, 2026-6pm CDT Jun 27, 2026
 
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Additional Resources

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Hourly Weather Forecast

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation