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.

Fair

2°C

36°F

Humidity 52%
Wind Speed N 15 km/h
Barometer 30.45 in
Dewpoint -7°C (19°F)
Visibility 16 km
Wind Chill-2°C (29°F)
Last update 7 Feb 10:45 am CST
Extended Forecast for

Simpson IL

  • Today

    Today: Sunny, with a high near 4. Northeast wind 5 to 10 km/h.

    High: 4 °C

    Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around -4. East southeast wind 5 to 8 km/h.

    Low: -4 °C

    Partly Cloudy

  • Sunday

    Sunday: Partly sunny, with a high near 8. Southeast wind 5 to 10 km/h becoming calm in the afternoon.

    High: 8 °C

    Partly Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around -1. Calm wind.

    Low: -1 °C

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 14. Calm wind.

    High: 14 °C

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 6. Calm wind.

    Low: 6 °C

    Mostly Clear

  • Tuesday

    Tuesday: Partly sunny, with a high near 19. Light south southwest wind becoming southwest 6 to 11 km/h in the morning.

    High: 19 °C

    Partly Sunny

  • Tuesday Night

    Tuesday Night: Showers likely, mainly after midnight. Mostly cloudy, with a low around 6. Calm wind.

    Low: 6 °C

    Showers
    Likely

  • Wednesday

    Wednesday: A chance of showers before noon. Mostly cloudy, with a high near 12. North wind 5 to 10 km/h.

    High: 12 °C

    Chance
    Showers then
    Partly Sunny

Detailed Forecast

Today
Sunny, with a high near 4. Northeast wind 5 to 10 km/h.
Tonight
Partly cloudy, with a low around -4. East southeast wind 5 to 8 km/h.
Sunday
Partly sunny, with a high near 8. Southeast wind 5 to 10 km/h becoming calm in the afternoon.
Sunday Night
Mostly clear, with a low around -1. Calm wind.
Monday
Sunny, with a high near 14. Calm wind.
Monday Night
Mostly clear, with a low around 6. Calm wind.
Tuesday
Partly sunny, with a high near 19. Light south southwest wind becoming southwest 6 to 11 km/h in the morning.
Tuesday Night
Showers likely, mainly after midnight. Mostly cloudy, with a low around 6. Calm wind.
Wednesday
A chance of showers before noon. Mostly cloudy, with a high near 12. North wind 5 to 10 km/h.
Wednesday Night
A slight chance of showers. Mostly cloudy, with a low around 1. Calm wind.
Thursday
A chance of showers. Mostly cloudy, with a high near 10. Calm wind becoming east 5 to 10 km/h in the morning.
Thursday Night
A chance of showers. Mostly cloudy, with a low around 2. Calm wind.
Friday
A chance of showers. Mostly cloudy, with a high near 9. East northeast wind 5 to 11 km/h.
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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:
10:52 am CST Feb 7, 2026
Forecast Valid:
11am CST Feb 7, 2026-6pm CST Feb 13, 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