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.

Overcast

73°F

23°C

Humidity 100%
Wind Speed NW 7 mph
Barometer 30.00 in
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Last update 17 Aug 6:52 am CDT
Extended Forecast for

Grand Tower IL

  • Today

    Today: Partly sunny, with a high near 86. Light northwest wind becoming north northwest 5 to 9 mph in the morning.

    High: 86 °F

    Partly Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 65. North wind around 6 mph becoming calm in the evening.

    Low: 65 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Sunny, with a high near 89. Calm wind.

    High: 89 °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 69. Light south southeast wind. Chance of precipitation is 30%.

    Low: 69 °F

    Mostly Clear
    then Chance
    Showers

  • Wednesday

    Wednesday: Showers likely and possibly a thunderstorm before 10am, then showers likely between 10am and 1pm, then a slight chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 91. Light and variable wind becoming south around 6 mph in the morning. Chance of precipitation is 70%.

    High: 91 °F

    Showers
    Likely

  • 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 69. Light northeast wind. Chance of precipitation is 70%.

    Low: 69 °F

    Chance
    T-storms then
    Showers
    Likely

  • Thursday

    Thursday: A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 84. North wind 3 to 5 mph.

    High: 84 °F

    Chance
    T-storms

  • Thursday Night

    Thursday Night: A chance of showers before 1am. Partly cloudy, with a low around 66. Light northeast wind.

    Low: 66 °F

    Chance
    Showers

  • Friday

    Friday: Mostly sunny, with a high near 84. Calm wind becoming north around 5 mph in the afternoon.

    High: 84 °F

    Mostly Sunny

Detailed Forecast

Today
Partly sunny, with a high near 86. Light northwest wind becoming north northwest 5 to 9 mph in the morning.
Tonight
Partly cloudy, with a low around 65. North wind around 6 mph becoming calm in the evening.
Tuesday
Sunny, with a high near 89. Calm wind.
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 69. Light south southeast wind. Chance of precipitation is 30%.
Wednesday
Showers likely and possibly a thunderstorm before 10am, then showers likely between 10am and 1pm, then a slight chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 91. Light and variable wind becoming south around 6 mph in the morning. Chance of precipitation is 70%.
Wednesday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 69. Light northeast wind. Chance of precipitation is 70%.
Thursday
A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 84. North wind 3 to 5 mph.
Thursday Night
A chance of showers before 1am. Partly cloudy, with a low around 66. Light northeast wind.
Friday
Mostly sunny, with a high near 84. Calm wind becoming north around 5 mph in the afternoon.
Friday Night
Mostly clear, with a low around 64. Light north wind.
Saturday
Sunny, with a high near 87. Calm wind becoming north northwest around 6 mph in the afternoon.
Saturday Night
Mostly clear, with a low around 65. Light north wind.
Sunday
Sunny, with a high near 85. Calm wind becoming north northwest around 5 mph in the afternoon.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Grand Tower IL
 37.62°N 89.49°W
Last Update:
6:46 am CDT Aug 17, 2026
Forecast Valid:
7am CDT Aug 17, 2026-6pm CDT Aug 23, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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