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

81°F

27°C

Humidity 42%
Wind Speed SW 6 mph
Barometer 30.01 in (1015.8 mb)
Dewpoint 56°F (13°C)
Visibility 10.00 mi
Heat Index81°F (27°C)
Last update 11 Oct 1:52 pm CDT
Extended Forecast for

Grand Tower IL

  • This Afternoon

    This Afternoon: Sunny, with a high near 85. Calm wind.

    High: 85 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 61. Light south wind.

    Low: 61 °F

    Mostly Clear

  • Columbus Day

    Columbus Day: Sunny, with a high near 91. Light south southwest wind becoming southwest 6 to 11 mph in the morning.

    High: 91 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 66. South southwest wind 5 to 7 mph.

    Low: 66 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 93. Southwest wind 5 to 9 mph.

    High: 93 °F

    Sunny

  • Tuesday Night

    Tuesday Night: A chance of showers between 1am and 4am, then a chance of showers and thunderstorms after 4am. Mostly clear, with a low around 70. South southwest wind around 5 mph. Chance of precipitation is 30%.

    Low: 70 °F

    Mostly Clear
    then Chance
    Showers

  • Wednesday

    Wednesday: Showers and possibly a thunderstorm. High near 86. South southwest wind 3 to 5 mph. Chance of precipitation is 80%.

    High: 86 °F

    Showers

  • Wednesday Night

    Wednesday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 64. Calm wind.

    Low: 64 °F

    Showers
    Likely

  • Thursday

    Thursday: Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 82. Light and variable wind becoming south 5 to 8 mph in the morning.

    High: 82 °F

    Showers
    Likely

Detailed Forecast

This Afternoon
Sunny, with a high near 85. Calm wind.
Tonight
Mostly clear, with a low around 61. Light south wind.
Columbus Day
Sunny, with a high near 91. Light south southwest wind becoming southwest 6 to 11 mph in the morning.
Monday Night
Mostly clear, with a low around 66. South southwest wind 5 to 7 mph.
Tuesday
Sunny, with a high near 93. Southwest wind 5 to 9 mph.
Tuesday Night
A chance of showers between 1am and 4am, then a chance of showers and thunderstorms after 4am. Mostly clear, with a low around 70. South southwest wind around 5 mph. Chance of precipitation is 30%.
Wednesday
Showers and possibly a thunderstorm. High near 86. South southwest wind 3 to 5 mph. Chance of precipitation is 80%.
Wednesday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 64. Calm wind.
Thursday
Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 82. Light and variable wind becoming south 5 to 8 mph in the morning.
Thursday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 56. West wind 5 to 9 mph.
Friday
Partly sunny, with a high near 68. North northwest wind 13 to 18 mph, with gusts as high as 25 mph.
Friday Night
Mostly clear, with a low around 41. North northwest wind 9 to 16 mph, with gusts as high as 23 mph.
Saturday
Sunny, with a high near 61. North wind 8 to 11 mph.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Grand Tower IL
 37.64°N 89.52°W
Last Update:
2:01 pm CDT Oct 11, 2026
Forecast Valid:
2pm CDT Oct 11, 2026-6pm CDT Oct 17, 2026
 
Forecast Discussion
 
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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

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation