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Hazardous Weather Conditions

Current conditions at

Southern Illinois Airport (KMDH)

Lat: 37.78°NLon: 89.25°WElev: 400ft.

Fair

74°F

23°C

Humidity 94%
Wind Speed Calm
Barometer 30.01 in (1015.7 mb)
Dewpoint 72°F (22°C)
Visibility 8.00 mi
Last update 19 Aug 1:52 am CDT
Extended Forecast for

4 Miles SW Vergennes IL

Heat Advisory August 19, 02:41am until August 19, 07:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 19, 02:41am until August 19, 07:00pm

    NOW until 7:00pm Tue

    Heat Advisory

  • Overnight

    Low: 78 °F

    Clear

  • Tuesday

    Tuesday: A 30 percent chance of showers and thunderstorms, mainly after 4pm. Sunny and hot, with a high near 97. Heat index values as high as 105. Calm wind becoming southwest around 6 mph in the morning.

    High: 97 °F

    Sunny then
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A 40 percent chance of showers and thunderstorms, mainly before 11pm. Partly cloudy, with a low around 72. North wind 3 to 6 mph.

    Low: 72 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: Mostly sunny, with a high near 89. North wind 6 to 10 mph.

    High: 89 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 66. North northeast wind 6 to 9 mph.

    Low: 66 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 87. North northeast wind 6 to 10 mph.

    High: 87 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 65. North northeast wind 5 to 8 mph becoming calm in the evening.

    Low: 65 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 90. Calm wind becoming north northeast around 6 mph in the morning.

    High: 90 °F

    Sunny

Detailed Forecast

Overnight
Clear, with a steady temperature around 78. Light south wind.
Tuesday
A 30 percent chance of showers and thunderstorms, mainly after 4pm. Sunny and hot, with a high near 97. Heat index values as high as 105. Calm wind becoming southwest around 6 mph in the morning.
Tuesday Night
A 40 percent chance of showers and thunderstorms, mainly before 11pm. Partly cloudy, with a low around 72. North wind 3 to 6 mph.
Wednesday
Mostly sunny, with a high near 89. North wind 6 to 10 mph.
Wednesday Night
Partly cloudy, with a low around 66. North northeast wind 6 to 9 mph.
Thursday
Mostly sunny, with a high near 87. North northeast wind 6 to 10 mph.
Thursday Night
Mostly clear, with a low around 65. North northeast wind 5 to 8 mph becoming calm in the evening.
Friday
Sunny, with a high near 90. Calm wind becoming north northeast around 6 mph in the morning.
Friday Night
Mostly clear, with a low around 65. North northeast wind around 6 mph becoming calm in the evening.
Saturday
Sunny, with a high near 91. Calm wind becoming north northwest 5 to 7 mph in the afternoon.
Saturday Night
Mostly clear, with a low around 63. North wind 3 to 6 mph.
Sunday
Sunny, with a high near 86. Light north northwest wind increasing to 5 to 9 mph in the morning.
Sunday Night
Mostly clear, with a low around 58. North wind 5 to 7 mph becoming calm in the evening.
Monday
Mostly sunny, with a high near 81. Calm wind becoming north northwest 5 to 7 mph in the morning.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
4 Miles SW Vergennes IL
 37.86°N 89.39°W
Last Update:
1:45 am CDT Aug 19, 2025
Forecast Valid:
2am CDT Aug 19, 2025-6pm CDT Aug 25, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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