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.

Partly Cloudy

79°F

26°C

Humidity 79%
Wind Speed S 8 mph
Barometer 29.88 in
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Heat Index82°F (28°C)
Last update 21 Jun 9:45 am CDT
Extended Forecast for

Herrin IL

Lake Wind Advisory June 21, 12:00pm until June 21, 07:00pm
Click here for hazard details and duration
Lake Wind Advisory

  • Today

    Today: A 40 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 89. South wind 8 to 17 mph, with gusts as high as 28 mph.

    High: 89 °F

    Partly Sunny
    then Chance
    T-storms

  • Tonight

    Tonight: Showers and thunderstorms, mainly before 2am, then showers likely and possibly a thunderstorm after 4am. Low around 69. South wind 9 to 16 mph, with gusts as high as 23 mph. Chance of precipitation is 90%.

    Low: 69 °F

    T-storms then
    Showers
    Likely

  • Monday

    Monday: A chance of showers and thunderstorms before 10am, then a chance of showers between 10am and noon. Mostly cloudy, with a high near 80. Northwest wind 8 to 10 mph. Chance of precipitation is 40%.

    High: 80 °F

    Chance
    Showers then
    Mostly Cloudy

  • Monday Night

    Monday Night: Partly cloudy, with a low around 63. North wind 5 to 8 mph becoming calm in the evening.

    Low: 63 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 83. Light north northeast wind.

    High: 83 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 64. Calm wind.

    Low: 64 °F

    Mostly Clear

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 86. Calm wind.

    High: 86 °F

    Sunny then
    Slight Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A slight chance of showers and thunderstorms. Partly cloudy, with a low around 66. Calm wind.

    Low: 66 °F

    Slight Chance
    T-storms

  • Thursday

    Thursday: A chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 86. Calm wind becoming west northwest around 6 mph in the afternoon.

    High: 86 °F

    Chance
    T-storms

Detailed Forecast

Today
A 40 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 89. South wind 8 to 17 mph, with gusts as high as 28 mph.
Tonight
Showers and thunderstorms, mainly before 2am, then showers likely and possibly a thunderstorm after 4am. Low around 69. South wind 9 to 16 mph, with gusts as high as 23 mph. Chance of precipitation is 90%.
Monday
A chance of showers and thunderstorms before 10am, then a chance of showers between 10am and noon. Mostly cloudy, with a high near 80. Northwest wind 8 to 10 mph. Chance of precipitation is 40%.
Monday Night
Partly cloudy, with a low around 63. North wind 5 to 8 mph becoming calm in the evening.
Tuesday
Mostly sunny, with a high near 83. Light north northeast wind.
Tuesday Night
Mostly clear, with a low around 64. Calm wind.
Wednesday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 86. Calm wind.
Wednesday Night
A slight chance of showers and thunderstorms. Partly cloudy, with a low around 66. Calm wind.
Thursday
A chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 86. Calm wind becoming west northwest around 6 mph in the afternoon.
Thursday Night
A slight chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 66. Light and variable wind.
Friday
A chance of showers and thunderstorms. Mostly sunny, with a high near 87. Calm wind becoming south southwest around 5 mph in the afternoon.
Friday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 69. South wind around 5 mph becoming calm in the evening.
Saturday
A chance of showers and thunderstorms. Partly sunny, with a high near 89. South southwest wind 5 to 13 mph, with gusts as high as 21 mph.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Herrin IL
 37.8°N 89.03°W
Last Update:
8:51 am CDT Jun 21, 2026
Forecast Valid:
10am CDT Jun 21, 2026-6pm CDT Jun 27, 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