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.

Fair

77°F

25°C

Humidity 74%
Wind Speed N 6 mph
Barometer 30.00 in
Dewpoint 68°F (20°C)
Visibility 10.00 mi
Heat Index79°F (26°C)
Last update 21 Sep 11:52 am CDT
Extended Forecast for

Grand Tower IL

  • This Afternoon

    This Afternoon: A slight chance of showers and thunderstorms before 3pm, then a slight chance of showers and thunderstorms after 4pm. Mostly cloudy, with a high near 82. North wind 3 to 6 mph. Chance of precipitation is 20%.

    High: 82 °F

    Slight Chance
    T-storms

  • Tonight

    Tonight: A 10 percent chance of showers and thunderstorms before 7pm. Mostly cloudy, with a low around 62. North wind 3 to 6 mph.

    Low: 62 °F

    Slight Chance
    T-storms

  • Tuesday

    Tuesday: Partly sunny, with a high near 77. North wind 5 to 8 mph.

    High: 77 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 57. North northeast wind 5 to 7 mph.

    Low: 57 °F

    Decreasing
    Clouds

  • Wednesday

    Wednesday: Mostly sunny, with a high near 76. North wind 6 to 9 mph.

    High: 76 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 54. North northeast wind around 6 mph becoming calm in the evening.

    Low: 54 °F

    Mostly Clear

  • Thursday

    Thursday: Mostly sunny, with a high near 77. North northeast wind 3 to 8 mph.

    High: 77 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 55. North northeast wind around 5 mph becoming calm in the evening.

    Low: 55 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 77. Northeast wind 3 to 7 mph.

    High: 77 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
A slight chance of showers and thunderstorms before 3pm, then a slight chance of showers and thunderstorms after 4pm. Mostly cloudy, with a high near 82. North wind 3 to 6 mph. Chance of precipitation is 20%.
Tonight
A 10 percent chance of showers and thunderstorms before 7pm. Mostly cloudy, with a low around 62. North wind 3 to 6 mph.
Tuesday
Partly sunny, with a high near 77. North wind 5 to 8 mph.
Tuesday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 57. North northeast wind 5 to 7 mph.
Wednesday
Mostly sunny, with a high near 76. North wind 6 to 9 mph.
Wednesday Night
Mostly clear, with a low around 54. North northeast wind around 6 mph becoming calm in the evening.
Thursday
Mostly sunny, with a high near 77. North northeast wind 3 to 8 mph.
Thursday Night
Partly cloudy, with a low around 55. North northeast wind around 5 mph becoming calm in the evening.
Friday
Mostly sunny, with a high near 77. Northeast wind 3 to 7 mph.
Friday Night
Partly cloudy, with a low around 54. Light east northeast wind.
Saturday
Mostly sunny, with a high near 76. Light northeast wind.
Saturday Night
Partly cloudy, with a low around 55. Calm wind.
Sunday
Mostly sunny, with a high near 82. Calm wind.
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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:
11:46 am CDT Sep 21, 2026
Forecast Valid:
1pm CDT Sep 21, 2026-6pm CDT Sep 27, 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

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation