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

72°F

22°C

Humidity 38%
Wind Speed W 3 mph
Barometer 30.12 in
Dewpoint 45°F (7°C)
Visibility 10.00 mi
Last update 9 Nov 3:45 pm CST
Extended Forecast for

Simpson IL

  • This Afternoon

    This Afternoon: Sunny, with a high near 73. Light south southwest wind.

    High: 73 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 41. Calm wind.

    Low: 41 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 70. Calm wind becoming west southwest around 5 mph.

    High: 70 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Clear, with a low around 44. Calm wind.

    Low: 44 °F

    Clear

  • Veterans Day

    Veterans Day: A 40 percent chance of showers after noon. Mostly sunny, with a high near 70. Light and variable wind becoming southwest 5 to 10 mph in the morning. Winds could gust as high as 18 mph.

    High: 70 °F

    Mostly Sunny
    then Chance
    Showers

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers before midnight. Partly cloudy, with a low around 43. North northwest wind 6 to 13 mph, with gusts as high as 21 mph.

    Low: 43 °F

    Slight Chance
    Showers then
    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 54. Northwest wind 11 to 15 mph, with gusts as high as 23 mph.

    High: 54 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 31. North northwest wind 5 to 10 mph, with gusts as high as 18 mph.

    Low: 31 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 49. North northwest wind 5 to 11 mph, with gusts as high as 18 mph.

    High: 49 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
Sunny, with a high near 73. Light south southwest wind.
Tonight
Mostly clear, with a low around 41. Calm wind.
Tuesday
Sunny, with a high near 70. Calm wind becoming west southwest around 5 mph.
Tuesday Night
Clear, with a low around 44. Calm wind.
Veterans Day
A 40 percent chance of showers after noon. Mostly sunny, with a high near 70. Light and variable wind becoming southwest 5 to 10 mph in the morning. Winds could gust as high as 18 mph.
Wednesday Night
A 20 percent chance of showers before midnight. Partly cloudy, with a low around 43. North northwest wind 6 to 13 mph, with gusts as high as 21 mph.
Thursday
Mostly sunny, with a high near 54. Northwest wind 11 to 15 mph, with gusts as high as 23 mph.
Thursday Night
Partly cloudy, with a low around 31. North northwest wind 5 to 10 mph, with gusts as high as 18 mph.
Friday
Mostly sunny, with a high near 49. North northwest wind 5 to 11 mph, with gusts as high as 18 mph.
Friday Night
Mostly clear, with a low around 27. Calm wind.
Saturday
Sunny, with a high near 53. Light north northwest wind.
Saturday Night
Mostly clear, with a low around 29. Calm wind.
Sunday
A slight chance of showers. Mostly sunny, with a high near 57. Calm wind becoming south around 6 mph.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Simpson IL
 37.46°N 88.77°W
Last Update:
3:31 pm CST Nov 9, 2026
Forecast Valid:
4pm CST Nov 9, 2026-6pm CST Nov 15, 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