National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

Marion - Williamson County Regional Airport (KMWA)

Lat: 37.77°NLon: 89.01°WElev: 486ft.

Fair

76°F

24°C

Humidity 92%
Wind Speed Calm
Barometer 30.02 in
Dewpoint 74°F (23°C)
Visibility 10.00 mi
Heat Index76°F (24°C)
Last update 19 Aug 3:55 am CDT
Extended Forecast for

Carterville IL

Heat Advisory August 19, 04:07am until August 19, 07:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 19, 04:07am until August 19, 07:00pm

    NOW until 7:00pm Tue

    Heat Advisory

  • Today

    High: 97 °F

    Sunny then
    Chance
    T-storms

  • Tonight

    Tonight: A 50 percent chance of showers and thunderstorms, mainly before midnight. Mostly cloudy, with a low around 72. Northwest wind around 5 mph becoming calm.

    Low: 72 °F

    Chance
    T-storms then
    Slight Chance
    T-storms

  • Wednesday

    Wednesday: A slight chance of showers and thunderstorms between 7am and 10am. Partly sunny, with a high near 89. North wind 6 to 10 mph. Chance of precipitation is 20%.

    High: 89 °F

    Slight Chance
    T-storms then
    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 67. North northeast wind 5 to 8 mph.

    Low: 67 °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 66. North northeast wind 5 to 7 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 6 mph in the morning.

    High: 90 °F

    Sunny

  • Friday Night

    Friday Night: Clear, with a low around 66. North northeast wind around 5 mph becoming calm in the evening.

    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 97. Heat index values as high as 105. Calm wind becoming west southwest around 6 mph in the morning.
Tonight
A 50 percent chance of showers and thunderstorms, mainly before midnight. Mostly cloudy, with a low around 72. Northwest wind around 5 mph becoming calm.
Wednesday
A slight chance of showers and thunderstorms between 7am and 10am. Partly sunny, with a high near 89. North wind 6 to 10 mph. Chance of precipitation is 20%.
Wednesday Night
Partly cloudy, with a low around 67. North northeast wind 5 to 8 mph.
Thursday
Mostly sunny, with a high near 87. North northeast wind 6 to 10 mph.
Thursday Night
Mostly clear, with a low around 66. North northeast wind 5 to 7 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
Clear, with a low around 66. North northeast wind around 5 mph becoming calm in the evening.
Saturday
Sunny, with a high near 91. Calm wind becoming north northwest around 6 mph in the afternoon.
Saturday Night
Mostly clear, with a low around 64. North wind around 6 mph becoming calm in the evening.
Sunday
Sunny, with a high near 86. North northwest wind 3 to 8 mph.
Sunday Night
Mostly clear, with a low around 58. North wind around 6 mph becoming calm in the evening.
Monday
Mostly sunny, with a high near 80. 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:
Carterville IL
 37.76°N 89.09°W
Last Update:
3:01 am CDT Aug 19, 2025
Forecast Valid:
4am CDT Aug 19, 2025-6pm CDT Aug 25, 2025
 
Forecast Discussion
 
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Additional Resources

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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