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Hazardous Weather Conditions

Current conditions at

Marion - Williamson County Regional Airport (KMWA)

Lat: 37.77°NLon: 89.01°WElev: 486ft.

Fair

91°F

33°C

Humidity 59%
Wind Speed SW 9 mph
Barometer 30.02 in
Dewpoint 75°F (24°C)
Visibility 10.00 mi
Heat Index102°F (39°C)
Last update 19 Aug 10:45 am CDT
Extended Forecast for

Simpson IL

Heat Advisory August 19, 10:57am until August 19, 07:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 19, 10:57am until August 19, 07:00pm

    NOW until 7:00pm Tue

    Heat Advisory

  • Today

    High: 98 °F

    Sunny then
    Chance
    T-storms

  • Tonight

    Tonight: A chance of showers and thunderstorms before 4am, then a slight chance of showers and thunderstorms after 5am. Mostly cloudy, with a low around 72. Light north wind. Chance of precipitation is 50%.

    Low: 72 °F

    Chance
    T-storms then
    Chance
    Showers

  • Wednesday

    Wednesday: A slight chance of showers and thunderstorms between 7am and 1pm. Mostly sunny, with a high near 89. North wind 3 to 8 mph. Chance of precipitation is 20%.

    High: 89 °F

    Slight Chance
    T-storms

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 67. North northeast wind around 6 mph becoming calm in the evening.

    Low: 67 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 87. North northeast wind 3 to 7 mph.

    High: 87 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 66. North northeast wind around 6 mph becoming calm in the evening.

    Low: 66 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 90. Calm wind becoming north northeast around 5 mph in the afternoon.

    High: 90 °F

    Sunny

  • Friday Night

    Friday Night: Clear, with a low around 66. Calm wind.

    Low: 66 °F

    Clear

Detailed Forecast

Today
A 30 percent chance of showers and thunderstorms, mainly after 4pm. Increasing clouds and hot, with a high near 98. Heat index values as high as 107. Light and variable wind becoming west southwest around 5 mph.
Tonight
A chance of showers and thunderstorms before 4am, then a slight chance of showers and thunderstorms after 5am. Mostly cloudy, with a low around 72. Light north wind. Chance of precipitation is 50%.
Wednesday
A slight chance of showers and thunderstorms between 7am and 1pm. Mostly sunny, with a high near 89. North wind 3 to 8 mph. Chance of precipitation is 20%.
Wednesday Night
Partly cloudy, with a low around 67. North northeast wind around 6 mph becoming calm in the evening.
Thursday
Mostly sunny, with a high near 87. North northeast wind 3 to 7 mph.
Thursday Night
Mostly clear, with a low around 66. North northeast wind around 6 mph becoming calm in the evening.
Friday
Sunny, with a high near 90. Calm wind becoming north northeast around 5 mph in the afternoon.
Friday Night
Clear, with a low around 66. Calm wind.
Saturday
Sunny, with a high near 92. Calm wind becoming north around 5 mph in the afternoon.
Saturday Night
Mostly clear, with a low around 64. Light north wind.
Sunday
Sunny, with a high near 87. Calm wind becoming north northwest around 6 mph in the morning.
Sunday Night
Mostly clear, with a low around 59. North wind around 5 mph becoming calm in the evening.
Monday
Sunny, with a high near 81. Calm wind becoming north around 5 mph in the afternoon.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Simpson IL
 37.46°N 88.77°W
Last Update:
9:46 am CDT Aug 19, 2025
Forecast Valid:
10am CDT Aug 19, 2025-6pm CDT Aug 25, 2025
 
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