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

57°F

14°C

Humidity 100%
Wind Speed SE 6 mph
Barometer 30.25 in
Dewpoint 57°F (14°C)
Visibility 0.25 mi
Last update 24 Dec 8:47 am CST
Extended Forecast for

Simpson IL

Dense Fog Advisory December 24, 08:56am until December 24, 12:00pm
Click here for hazard details and duration
Dense Fog Advisory
  •  
    Dense Fog Advisory December 24, 08:56am until December 24, 12:00pm

    NOW until 12:00pm Wed

    Dense Fog Advisory

  • Today

    High: 67 °F

    Patchy
    Drizzle and
    Dense Fog
    then Mostly
    Cloudy

  • Tonight

    Tonight: Mostly cloudy, with a low around 57. Southwest wind around 6 mph.

    Low: 57 °F

    Mostly Cloudy

  • Christmas Day

    Christmas Day: Mostly cloudy, with a high near 69. Southwest wind 3 to 6 mph.

    High: 69 °F

    Mostly Cloudy

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 59. Calm wind becoming south southwest 5 to 7 mph after midnight.

    Low: 59 °F

    Mostly Cloudy

  • Friday

    Friday: Partly sunny, with a high near 71. West southwest wind 6 to 11 mph, with gusts as high as 21 mph.

    High: 71 °F

    Partly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 52. Light west southwest wind.

    Low: 52 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly cloudy, with a high near 70. Calm wind becoming south 5 to 8 mph in the morning.

    High: 70 °F

    Mostly Cloudy

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 52. South wind around 7 mph becoming west after midnight. Winds could gust as high as 18 mph.

    Low: 52 °F

    Mostly Cloudy

Detailed Forecast

Today
Patchy drizzle before noon. Widespread dense fog before 9am. Otherwise, cloudy, with a high near 67. Calm wind becoming south around 6 mph in the afternoon.
Tonight
Mostly cloudy, with a low around 57. Southwest wind around 6 mph.
Christmas Day
Mostly cloudy, with a high near 69. Southwest wind 3 to 6 mph.
Thursday Night
Mostly cloudy, with a low around 59. Calm wind becoming south southwest 5 to 7 mph after midnight.
Friday
Partly sunny, with a high near 71. West southwest wind 6 to 11 mph, with gusts as high as 21 mph.
Friday Night
Partly cloudy, with a low around 52. Light west southwest wind.
Saturday
Mostly cloudy, with a high near 70. Calm wind becoming south 5 to 8 mph in the morning.
Saturday Night
Mostly cloudy, with a low around 52. South wind around 7 mph becoming west after midnight. Winds could gust as high as 18 mph.
Sunday
A chance of showers. Mostly cloudy, with a high near 62. Northwest wind 7 to 13 mph, with gusts as high as 24 mph.
Sunday Night
A slight chance of rain and snow showers before midnight. Partly cloudy, with a low around 20. Northwest wind 7 to 10 mph, with gusts as high as 20 mph.
Monday
Sunny, with a high near 29. Northwest wind 6 to 10 mph, with gusts as high as 20 mph.
Monday Night
Mostly clear, with a low around 16. Northwest wind around 5 mph becoming calm in the evening.
Tuesday
Mostly sunny, with a high near 33. Calm wind becoming west 5 to 7 mph in the morning.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Simpson IL
 37.46°N 88.77°W
Last Update:
7:11 am CST Dec 24, 2025
Forecast Valid:
8am CST Dec 24, 2025-6pm CST Dec 30, 2025
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation