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

74°F

23°C

Humidity 92%
Wind Speed S 3 mph
Barometer 30.05 in
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Last update 1 Sep 3:35 am CDT
Extended Forecast for

Marion IL

Heat Advisory September 1, 03:49am until September 4, 08:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory September 1, 03:49am until September 4, 08:00pm

    NOW until 8:00pm Fri

    Heat Advisory

  • Overnight

    Low: 73 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny and hot, with a high near 99. South southwest wind 3 to 7 mph.

    High: 99 °F

    Hot

  • Tuesday Night

    Tuesday Night: Clear, with a low around 75. South wind around 5 mph becoming calm in the evening.

    Low: 75 °F

    Clear

  • Wednesday

    Wednesday: Sunny and hot, with a high near 99. Calm wind becoming south southwest 5 to 8 mph in the morning.

    High: 99 °F

    Hot

  • Wednesday Night

    Wednesday Night: Clear, with a low around 74. South wind around 5 mph becoming calm in the evening.

    Low: 74 °F

    Clear

  • Thursday

    Thursday: Sunny and hot, with a high near 99. Calm wind becoming south southwest 5 to 7 mph in the morning.

    High: 99 °F

    Hot

  • Thursday Night

    Thursday Night: Clear, with a low around 76. Light and variable wind.

    Low: 76 °F

    Clear

  • Friday

    Friday: Sunny and hot, with a high near 99. Calm wind becoming south southwest around 5 mph in the afternoon.

    High: 99 °F

    Hot

Detailed Forecast

Overnight
Mostly clear, with a low around 73. Light south southwest wind.
Tuesday
Sunny and hot, with a high near 99. South southwest wind 3 to 7 mph.
Tuesday Night
Clear, with a low around 75. South wind around 5 mph becoming calm in the evening.
Wednesday
Sunny and hot, with a high near 99. Calm wind becoming south southwest 5 to 8 mph in the morning.
Wednesday Night
Clear, with a low around 74. South wind around 5 mph becoming calm in the evening.
Thursday
Sunny and hot, with a high near 99. Calm wind becoming south southwest 5 to 7 mph in the morning.
Thursday Night
Clear, with a low around 76. Light and variable wind.
Friday
Sunny and hot, with a high near 99. Calm wind becoming south southwest around 5 mph in the afternoon.
Friday Night
Mostly clear, with a low around 75. Calm wind.
Saturday
Sunny and hot, with a high near 99. Calm wind becoming west around 5 mph in the afternoon.
Saturday Night
A slight chance of showers and thunderstorms. Mostly clear, with a low around 72. Calm wind.
Sunday
A slight chance of showers and thunderstorms. Mostly sunny, with a high near 96. Calm wind becoming north northeast around 6 mph in the afternoon.
Sunday Night
Partly cloudy, with a low around 70. Light east northeast wind.
Labor Day
Mostly sunny, with a high near 94. Calm wind becoming east 5 to 8 mph in the afternoon.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Marion IL
 37.73°N 88.92°W
Last Update:
1:26 am CDT Sep 1, 2026
Forecast Valid:
3am CDT Sep 1, 2026-6pm CDT Sep 7, 2026
 
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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