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

82°F

28°C

Humidity 30%
Wind Speed W 8 G 18 mph
Barometer 29.90 in
Dewpoint 48°F (9°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 20 Mar 2:45 pm CDT
Extended Forecast for

Simpson IL

  • This Afternoon

    This Afternoon: Sunny, with a high near 83. Southwest wind around 9 mph.

    High: 83 °F

    Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 56. Southwest wind around 6 mph becoming calm in the evening.

    Low: 56 °F

    Increasing
    Clouds

  • Saturday

    Saturday: Sunny, with a high near 83. Calm wind becoming west southwest around 5 mph in the afternoon.

    High: 83 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 62. Calm wind becoming south southwest around 5 mph after midnight.

    Low: 62 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 85. South southwest wind 6 to 11 mph, with gusts as high as 24 mph.

    High: 85 °F

    Sunny

  • Sunday Night

    Sunday Night: A slight chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 1am. Partly cloudy, with a low around 42. West southwest wind 8 to 10 mph becoming north after midnight. Winds could gust as high as 23 mph. Chance of precipitation is 20%.

    Low: 42 °F

    Slight Chance
    T-storms then
    Slight Chance
    Showers

  • Monday

    Monday: Sunny, with a high near 60. North northeast wind 7 to 9 mph, with gusts as high as 20 mph.

    High: 60 °F

    Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 41. North northeast wind around 5 mph becoming calm in the evening.

    Low: 41 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 62. Calm wind becoming southeast around 5 mph.

    High: 62 °F

    Mostly Cloudy

Detailed Forecast

This Afternoon
Sunny, with a high near 83. Southwest wind around 9 mph.
Tonight
Increasing clouds, with a low around 56. Southwest wind around 6 mph becoming calm in the evening.
Saturday
Sunny, with a high near 83. Calm wind becoming west southwest around 5 mph in the afternoon.
Saturday Night
Mostly clear, with a low around 62. Calm wind becoming south southwest around 5 mph after midnight.
Sunday
Sunny, with a high near 85. South southwest wind 6 to 11 mph, with gusts as high as 24 mph.
Sunday Night
A slight chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 1am. Partly cloudy, with a low around 42. West southwest wind 8 to 10 mph becoming north after midnight. Winds could gust as high as 23 mph. Chance of precipitation is 20%.
Monday
Sunny, with a high near 60. North northeast wind 7 to 9 mph, with gusts as high as 20 mph.
Monday Night
Partly cloudy, with a low around 41. North northeast wind around 5 mph becoming calm in the evening.
Tuesday
Mostly cloudy, with a high near 62. Calm wind becoming southeast around 5 mph.
Tuesday Night
Mostly cloudy, with a low around 45. Calm wind.
Wednesday
A slight chance of showers. Partly sunny, with a high near 69. Light and variable wind becoming east southeast 5 to 7 mph in the morning.
Wednesday Night
Partly cloudy, with a low around 51. South southeast wind 3 to 5 mph.
Thursday
Sunny, with a high near 80. South southwest wind 6 to 11 mph, with gusts as high as 23 mph.
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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:
1:26 pm CDT Mar 20, 2026
Forecast Valid:
4pm CDT Mar 20, 2026-6pm CDT Mar 26, 2026
 
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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