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

75°F

24°C

Humidity 39%
Wind Speed SE 7 mph
Barometer 30.09 in
Dewpoint 48°F (9°C)
Visibility 10.00 mi
Last update 6 Oct 12:45 pm CDT
Extended Forecast for

Johnston City IL

  • This Afternoon

    This Afternoon: Sunny, with a high near 78. South southeast wind 3 to 5 mph.

    High: 78 °F

    Sunny

  • Tonight

    Tonight: Clear, with a low around 52. Calm wind.

    Low: 52 °F

    Clear

  • Wednesday

    Wednesday: Sunny, with a high near 87. Calm wind becoming west southwest 5 to 8 mph in the morning.

    High: 87 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 57. South southwest wind around 5 mph becoming calm in the evening.

    Low: 57 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 85. Calm wind becoming north northeast 5 to 7 mph in the morning.

    High: 85 °F

    Sunny

  • Thursday Night

    Thursday Night: Clear, with a low around 52. Light north northeast wind.

    Low: 52 °F

    Clear

  • Friday

    Friday: Sunny, with a high near 84. Southeast wind 3 to 7 mph.

    High: 84 °F

    Sunny

  • Friday Night

    Friday Night: Clear, with a low around 57. Light east southeast wind.

    Low: 57 °F

    Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 86. Light south southeast wind becoming south 6 to 11 mph in the morning.

    High: 86 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
Sunny, with a high near 78. South southeast wind 3 to 5 mph.
Tonight
Clear, with a low around 52. Calm wind.
Wednesday
Sunny, with a high near 87. Calm wind becoming west southwest 5 to 8 mph in the morning.
Wednesday Night
Mostly clear, with a low around 57. South southwest wind around 5 mph becoming calm in the evening.
Thursday
Sunny, with a high near 85. Calm wind becoming north northeast 5 to 7 mph in the morning.
Thursday Night
Clear, with a low around 52. Light north northeast wind.
Friday
Sunny, with a high near 84. Southeast wind 3 to 7 mph.
Friday Night
Clear, with a low around 57. Light east southeast wind.
Saturday
Mostly sunny, with a high near 86. Light south southeast wind becoming south 6 to 11 mph in the morning.
Saturday Night
A chance of showers, with thunderstorms also possible after 1am. Partly cloudy, with a low around 58. East southeast wind around 7 mph.
Sunday
A chance of showers. Partly sunny, with a high near 77. East southeast wind 7 to 11 mph.
Sunday Night
Mostly cloudy, with a low around 57. Light and variable wind.
Columbus Day
Mostly sunny, with a high near 81. Calm wind becoming north northwest 5 to 8 mph in the morning.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Johnston City IL
 37.85°N 88.94°W
Last Update:
1:16 pm CDT Oct 6, 2026
Forecast Valid:
1pm CDT Oct 6, 2026-6pm CDT Oct 12, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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