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.

Fog/Mist

68°F

20°C

Humidity 96%
Wind Speed Calm
Barometer 29.97 in
Dewpoint 67°F (19°C)
Visibility 4.00 mi
Last update 13 Aug 5:15 am CDT
Extended Forecast for

Simpson IL

  • Today

    Today: A 20 percent chance of showers and thunderstorms after 3pm. Patchy fog before 9am. Otherwise, mostly sunny, with a high near 92. Light northwest wind.

    High: 92 °F

    Patchy Fog
    then Slight
    Chance
    T-storms

  • Tonight

    Tonight: A chance of showers and thunderstorms before 1am, then a slight chance of showers after 4am. Patchy fog after midnight. Otherwise, mostly cloudy, with a low around 70. Calm wind. Chance of precipitation is 30%.

    Low: 70 °F

    Chance
    T-storms then
    Chance
    Showers and
    Patchy Fog

  • Thursday

    Thursday: A 10 percent chance of showers before 7am. Patchy fog before 7am. Otherwise, mostly sunny, with a high near 90. Calm wind.

    High: 90 °F

    Patchy Fog
    then Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 69. Calm wind.

    Low: 69 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 94. Calm wind.

    High: 94 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 72. Calm wind.

    Low: 72 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny and hot, with a high near 97. Calm wind.

    High: 97 °F

    Hot

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 73. Calm wind.

    Low: 73 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny and hot, with a high near 97. Calm wind.

    High: 97 °F

    Hot

Detailed Forecast

Today
A 20 percent chance of showers and thunderstorms after 3pm. Patchy fog before 9am. Otherwise, mostly sunny, with a high near 92. Light northwest wind.
Tonight
A chance of showers and thunderstorms before 1am, then a slight chance of showers after 4am. Patchy fog after midnight. Otherwise, mostly cloudy, with a low around 70. Calm wind. Chance of precipitation is 30%.
Thursday
A 10 percent chance of showers before 7am. Patchy fog before 7am. Otherwise, mostly sunny, with a high near 90. Calm wind.
Thursday Night
Mostly clear, with a low around 69. Calm wind.
Friday
Sunny, with a high near 94. Calm wind.
Friday Night
Mostly clear, with a low around 72. Calm wind.
Saturday
Sunny and hot, with a high near 97. Calm wind.
Saturday Night
Mostly clear, with a low around 73. Calm wind.
Sunday
Sunny and hot, with a high near 97. Calm wind.
Sunday Night
Mostly clear, with a low around 73. Calm wind.
Monday
Sunny and hot, with a high near 98. Light and variable wind.
Monday Night
Mostly clear, with a low around 72. Calm wind.
Tuesday
A slight chance of showers and thunderstorms. Sunny and hot, with a high near 97. Calm wind becoming north northwest around 5 mph in the afternoon.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Simpson IL
 37.46°N 88.77°W
Last Update:
4:30 am CDT Aug 13, 2025
Forecast Valid:
5am CDT Aug 13, 2025-6pm CDT Aug 19, 2025
 
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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