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

Marion - Williamson County Regional Airport (KMWA)

Lat: 37.77°NLon: 89.01°WElev: 486ft.

Partly Cloudy

66°F

19°C

Humidity 83%
Wind Speed SW 6 mph
Barometer 29.72 in
Dewpoint 61°F (16°C)
Visibility 10.00 mi
Last update 15 Nov 6:45 pm CST
Extended Forecast for

3 Miles SW Simpson IL

  • Tonight

    Tonight: Mostly cloudy, then gradually becoming clear, with a low around 47. North wind 6 to 8 mph.

    Low: 47 °F

    Decreasing
    Clouds

  • Sunday

    Sunday: Sunny, with a high near 60. North wind 6 to 9 mph.

    High: 60 °F

    Sunny

  • Sunday Night

    Sunday Night: Clear, with a low around 35. Calm wind.

    Low: 35 °F

    Clear

  • Monday

    Monday: A 20 percent chance of showers after noon. Increasing clouds, with a high near 61. Calm wind becoming southeast around 6 mph in the morning.

    High: 61 °F

    Sunny then
    Slight Chance
    Showers

  • Monday Night

    Monday Night: A chance of showers, then showers likely and possibly a thunderstorm after midnight. Mostly cloudy, with a low around 48. Southeast wind 5 to 7 mph. Chance of precipitation is 70%.

    Low: 48 °F

    Showers
    Likely

  • Tuesday

    Tuesday: A chance of showers and thunderstorms before noon, then a slight chance of showers. Partly sunny, with a high near 73. South southwest wind 7 to 11 mph, with gusts as high as 20 mph. Chance of precipitation is 50%.

    High: 73 °F

    Chance
    T-storms then
    Slight Chance
    Showers

  • Tuesday Night

    Tuesday Night: A 40 percent chance of showers. Mostly cloudy, with a low around 54. Southwest wind 3 to 6 mph.

    Low: 54 °F

    Chance
    Showers

  • Wednesday

    Wednesday: A chance of showers. Mostly cloudy, with a high near 69. Southwest wind 3 to 6 mph.

    High: 69 °F

    Chance
    Showers

  • Wednesday Night

    Wednesday Night: Showers likely, mainly after midnight. Mostly cloudy, with a low around 56. Light south wind.

    Low: 56 °F

    Showers
    Likely

Detailed Forecast

Tonight
Mostly cloudy, then gradually becoming clear, with a low around 47. North wind 6 to 8 mph.
Sunday
Sunny, with a high near 60. North wind 6 to 9 mph.
Sunday Night
Clear, with a low around 35. Calm wind.
Monday
A 20 percent chance of showers after noon. Increasing clouds, with a high near 61. Calm wind becoming southeast around 6 mph in the morning.
Monday Night
A chance of showers, then showers likely and possibly a thunderstorm after midnight. Mostly cloudy, with a low around 48. Southeast wind 5 to 7 mph. Chance of precipitation is 70%.
Tuesday
A chance of showers and thunderstorms before noon, then a slight chance of showers. Partly sunny, with a high near 73. South southwest wind 7 to 11 mph, with gusts as high as 20 mph. Chance of precipitation is 50%.
Tuesday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 54. Southwest wind 3 to 6 mph.
Wednesday
A chance of showers. Mostly cloudy, with a high near 69. Southwest wind 3 to 6 mph.
Wednesday Night
Showers likely, mainly after midnight. Mostly cloudy, with a low around 56. Light south wind.
Thursday
Showers, with thunderstorms also possible after noon. Mostly cloudy, with a high near 68. South wind 5 to 9 mph.
Thursday Night
Showers and possibly a thunderstorm. Mostly cloudy, with a low around 56. South wind around 8 mph.
Friday
Showers likely. Partly sunny, with a high near 66. Southwest wind 8 to 11 mph, with gusts as high as 21 mph.
Friday Night
A chance of showers. Partly cloudy, with a low around 45. Southwest wind 5 to 7 mph becoming west northwest after midnight.
Saturday
A slight chance of showers. Mostly sunny, with a high near 58. West northwest wind 5 to 7 mph.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
3 Miles SW Simpson IL
 37.44°N 88.8°W
Last Update:
8:02 pm CST Nov 15, 2025
Forecast Valid:
9pm CST Nov 15, 2025-6pm CST Nov 22, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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