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.

A Few Clouds

55°F

13°C

Humidity 47%
Wind Speed N 12 mph
Barometer 30.39 in
Dewpoint 36°F (2°C)
Visibility 10.00 mi
Wind Chill52°F (11°C)
Last update 7 Apr 12:45 pm CDT
Extended Forecast for

Johnston City IL

  • This Afternoon

    This Afternoon: Sunny, with a high near 59. East northeast wind around 10 mph.

    High: 59 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 41. East wind around 7 mph.

    Low: 41 °F

    Mostly Clear

  • Wednesday

    Wednesday: Mostly sunny, with a high near 74. South wind 6 to 10 mph.

    High: 74 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 54. South wind 7 to 9 mph.

    Low: 54 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 77. South southwest wind 9 to 11 mph, with gusts as high as 20 mph.

    High: 77 °F

    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 56. South wind around 7 mph.

    Low: 56 °F

    Mostly Clear

  • Friday

    Friday: A 30 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 78. South southwest wind 7 to 10 mph.

    High: 78 °F

    Mostly Sunny
    then Chance
    Showers

  • Friday Night

    Friday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 57. Northeast wind 3 to 5 mph.

    Low: 57 °F

    Chance
    T-storms

  • Saturday

    Saturday: Partly sunny, with a high near 80. East northeast wind around 6 mph becoming southeast in the afternoon.

    High: 80 °F

    Partly Sunny

Detailed Forecast

This Afternoon
Sunny, with a high near 59. East northeast wind around 10 mph.
Tonight
Mostly clear, with a low around 41. East wind around 7 mph.
Wednesday
Mostly sunny, with a high near 74. South wind 6 to 10 mph.
Wednesday Night
Mostly clear, with a low around 54. South wind 7 to 9 mph.
Thursday
Sunny, with a high near 77. South southwest wind 9 to 11 mph, with gusts as high as 20 mph.
Thursday Night
Mostly clear, with a low around 56. South wind around 7 mph.
Friday
A 30 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 78. South southwest wind 7 to 10 mph.
Friday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 57. Northeast wind 3 to 5 mph.
Saturday
Partly sunny, with a high near 80. East northeast wind around 6 mph becoming southeast in the afternoon.
Saturday Night
Partly cloudy, with a low around 61. East southeast wind around 6 mph.
Sunday
Mostly sunny, with a high near 84. South wind 6 to 15 mph, with gusts as high as 24 mph.
Sunday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 67. South wind 11 to 15 mph, with gusts as high as 25 mph.
Monday
A chance of showers and thunderstorms. Mostly cloudy, with a high near 81. Breezy, with a south southwest wind 16 to 20 mph, with gusts as high as 30 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:
1:27 pm CDT Apr 7, 2026
Forecast Valid:
1pm CDT Apr 7, 2026-6pm CDT Apr 13, 2026
 
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