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

84°F

29°C

Humidity 67%
Wind Speed SW 15 G 25 mph
Barometer 29.73 in (1006.1 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Heat Index90°F (32°C)
Last update 21 Jun 6:52 pm CDT
Extended Forecast for

Grand Tower IL

Tornado Watch June 21, 07:52pm until June 21, 09:00pm
Click here for hazard details and duration
...
  •  
    Tornado Watch June 21, 07:52pm until June 21, 09:00pm

    NOW until 9:00pm Sun

    Tornado Watch

  • Tonight

    Low: 69 °F

    T-storms

  • Monday

    Monday: A 30 percent chance of showers and thunderstorms, mainly before 11am. Cloudy, then gradually becoming mostly sunny, with a high near 80. North northwest wind 7 to 9 mph.

    High: 80 °F

    Chance
    T-storms then
    Partly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 62. North wind 5 to 8 mph becoming calm in the evening.

    Low: 62 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Sunny, with a high near 84. Light northeast wind.

    High: 84 °F

    Sunny

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers after 1am. Mostly clear, with a low around 63. Light east southeast wind.

    Low: 63 °F

    Mostly Clear
    then Slight
    Chance
    Showers

  • Wednesday

    Wednesday: A 40 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 86. Light south wind.

    High: 86 °F

    Mostly Sunny
    then Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 69. Light and variable wind. Chance of precipitation is 20%.

    Low: 69 °F

    Slight Chance
    T-storms

  • Thursday

    Thursday: A chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 88. Light southwest wind.

    High: 88 °F

    Chance
    T-storms

Detailed Forecast

Tonight
Showers and thunderstorms before 1am, then showers likely and possibly a thunderstorm between 1am and 4am, then a chance of showers and thunderstorms after 4am. Low around 69. South wind 6 to 11 mph becoming west after midnight. Winds could gust as high as 24 mph. Chance of precipitation is 90%.
Monday
A 30 percent chance of showers and thunderstorms, mainly before 11am. Cloudy, then gradually becoming mostly sunny, with a high near 80. North northwest wind 7 to 9 mph.
Monday Night
Partly cloudy, with a low around 62. North wind 5 to 8 mph becoming calm in the evening.
Tuesday
Sunny, with a high near 84. Light northeast wind.
Tuesday Night
A 20 percent chance of showers after 1am. Mostly clear, with a low around 63. Light east southeast wind.
Wednesday
A 40 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 86. Light south wind.
Wednesday Night
A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 69. Light and variable wind. Chance of precipitation is 20%.
Thursday
A chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 88. Light southwest wind.
Thursday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 67. Light and variable wind.
Friday
A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 88. Light south southeast wind.
Friday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 71. South wind around 5 mph becoming calm in the evening.
Saturday
A chance of showers and thunderstorms. Partly sunny, with a high near 90. South southwest wind 5 to 9 mph.
Saturday Night
A slight chance of showers and thunderstorms. Partly cloudy, with a low around 74. South wind 7 to 10 mph.
Sunday
A slight chance of showers and thunderstorms. Mostly sunny, with a high near 93. Breezy, with a south southwest wind 9 to 14 mph increasing to 15 to 20 mph in the afternoon. Winds could gust as high as 29 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:
5:46 pm CDT Jun 21, 2026
Forecast Valid:
7pm CDT Jun 21, 2026-6pm CDT Jun 28, 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