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.

N/A

Humidity NA
Wind Speed NA
Barometer NA
Dewpoint N/A
Visibility NA
Last update *** Not a current observation ***
Extended Forecast for

Johnston City IL

Dense Fog Advisory until November 24, 10:00am
Click here for hazard details and duration
...
  •  
    Dense Fog Advisory until November 24, 10:00am

    NOW until 10:00am Mon

    Dense Fog Advisory

  • Today

    High: 54 °F

    Dense Fog
    then Chance
    Showers

  • Tonight

    Tonight: Showers. Temperature rising to around 56 by 3am. Southeast wind 3 to 6 mph. Chance of precipitation is 90%.

    Low: 52 °F⇑

    Showers

  • Tuesday

    Tuesday: A 40 percent chance of showers, mainly before noon. Mostly cloudy, with a high near 64. West wind 3 to 7 mph.

    High: 64 °F

    Chance
    Showers

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers before midnight. Partly cloudy, with a low around 38. Light west southwest wind becoming west northwest 8 to 13 mph in the evening. Winds could gust as high as 22 mph.

    Low: 38 °F

    Slight Chance
    Showers then
    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 47. West northwest wind 10 to 18 mph, with gusts as high as 25 mph.

    High: 47 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 29. West northwest wind 6 to 8 mph.

    Low: 29 °F

    Partly Cloudy

  • Thanksgiving Day

    Thanksgiving Day: Sunny, with a high near 44. West northwest wind 6 to 11 mph.

    High: 44 °F

    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 24. Light northwest wind.

    Low: 24 °F

    Mostly Clear

Detailed Forecast

Today
A 50 percent chance of showers, mainly after 1pm. Widespread dense fog, mainly before 10am. Otherwise, cloudy, with a high near 54. Calm wind becoming south southeast 5 to 7 mph in the morning.
Tonight
Showers. Temperature rising to around 56 by 3am. Southeast wind 3 to 6 mph. Chance of precipitation is 90%.
Tuesday
A 40 percent chance of showers, mainly before noon. Mostly cloudy, with a high near 64. West wind 3 to 7 mph.
Tuesday Night
A 20 percent chance of showers before midnight. Partly cloudy, with a low around 38. Light west southwest wind becoming west northwest 8 to 13 mph in the evening. Winds could gust as high as 22 mph.
Wednesday
Mostly sunny, with a high near 47. West northwest wind 10 to 18 mph, with gusts as high as 25 mph.
Wednesday Night
Partly cloudy, with a low around 29. West northwest wind 6 to 8 mph.
Thanksgiving Day
Sunny, with a high near 44. West northwest wind 6 to 11 mph.
Thursday Night
Mostly clear, with a low around 24. Light northwest wind.
Friday
Mostly sunny, with a high near 43. Calm wind becoming northwest around 6 mph.
Friday Night
A chance of rain and snow showers. Mostly cloudy, with a low around 31. Calm wind becoming southeast around 6 mph after midnight.
Saturday
Rain and snow showers likely. Cloudy, with a high near 44. South southeast wind 6 to 10 mph.
Saturday Night
Showers likely. Cloudy, with a low around 38. South wind 6 to 8 mph.
Sunday
Showers likely. Cloudy, with a high near 53. South wind 7 to 9 mph.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Johnston City IL
 37.82°N 88.91°W
Last Update:
3:16 am CST Nov 24, 2025
Forecast Valid:
6am CST Nov 24, 2025-6pm CST Nov 30, 2025
 
Forecast Discussion
 
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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