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

74°F

23°C

Humidity 69%
Wind Speed S 12 mph
Barometer 29.87 in (1011.0 mb)
Dewpoint 63°F (17°C)
Visibility 10.00 mi
Last update 16 May 4:52 am CDT
Extended Forecast for

Grand Tower IL

  • Overnight

    Overnight: A 30 percent chance of showers and thunderstorms. Cloudy, with a steady temperature around 74. South wind around 7 mph, with gusts as high as 20 mph.

    Low: 74 °F

    Chance
    T-storms

  • Saturday

    Saturday: Showers and thunderstorms likely, mainly before 8am. Mostly cloudy, with a high near 87. South southwest wind around 11 mph, with gusts as high as 22 mph. Chance of precipitation is 60%.

    High: 87 °F

    Showers
    Likely then
    Chance
    T-storms

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 66. South southeast wind around 8 mph.

    Low: 66 °F

    Partly Cloudy

  • Sunday

    Sunday: Sunny, with a high near 90. South wind 8 to 15 mph, with gusts as high as 25 mph.

    High: 90 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 70. South wind around 14 mph, with gusts as high as 23 mph.

    Low: 70 °F

    Mostly Clear

  • Monday

    Monday: A 40 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 90. South wind 14 to 17 mph, with gusts as high as 28 mph.

    High: 90 °F

    Partly Sunny
    then Chance
    T-storms

  • Monday Night

    Monday Night: A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 1am, then a slight chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 71. South wind 13 to 16 mph, with gusts as high as 25 mph. Chance of precipitation is 30%.

    Low: 71 °F

    Chance
    Showers

  • Tuesday

    Tuesday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 88. South southwest wind 13 to 15 mph, with gusts as high as 25 mph.

    High: 88 °F

    Chance
    T-storms then
    Showers
    Likely

  • Tuesday Night

    Tuesday Night: Showers and possibly a thunderstorm. Mostly cloudy, with a low around 63. South southwest wind 6 to 9 mph becoming northwest after midnight.

    Low: 63 °F

    Showers

Detailed Forecast

Overnight
A 30 percent chance of showers and thunderstorms. Cloudy, with a steady temperature around 74. South wind around 7 mph, with gusts as high as 20 mph.
Saturday
Showers and thunderstorms likely, mainly before 8am. Mostly cloudy, with a high near 87. South southwest wind around 11 mph, with gusts as high as 22 mph. Chance of precipitation is 60%.
Saturday Night
Partly cloudy, with a low around 66. South southeast wind around 8 mph.
Sunday
Sunny, with a high near 90. South wind 8 to 15 mph, with gusts as high as 25 mph.
Sunday Night
Mostly clear, with a low around 70. South wind around 14 mph, with gusts as high as 23 mph.
Monday
A 40 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 90. South wind 14 to 17 mph, with gusts as high as 28 mph.
Monday Night
A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 1am, then a slight chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 71. South wind 13 to 16 mph, with gusts as high as 25 mph. Chance of precipitation is 30%.
Tuesday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 88. South southwest wind 13 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
Showers and possibly a thunderstorm. Mostly cloudy, with a low around 63. South southwest wind 6 to 9 mph becoming northwest after midnight.
Wednesday
A chance of showers and thunderstorms. Mostly cloudy, with a high near 76. North wind around 9 mph.
Wednesday Night
A slight chance of showers. Mostly cloudy, with a low around 56. North wind 6 to 8 mph.
Thursday
A slight chance of showers. Partly sunny, with a high near 75. North northeast wind around 8 mph.
Thursday Night
A slight chance of showers. Partly cloudy, with a low around 55. North northeast wind 5 to 8 mph becoming calm after midnight.
Friday
A slight chance of showers. Mostly sunny, with a high near 79. Northeast wind 3 to 6 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:
4:36 am CDT May 16, 2026
Forecast Valid:
5am CDT May 16, 2026-6pm CDT May 22, 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