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

49°F

9°C

Humidity 95%
Wind Speed Calm
Barometer 30.32 in
Dewpoint 48°F (9°C)
Visibility 10.00 mi
Last update 9 Oct 10:15 pm CDT
Extended Forecast for

Johnston City IL

  • Tonight

    Tonight: Clear, with a low around 42. Calm wind.

    Low: 42 °F

    Clear

  • Friday

    Friday: Sunny, with a high near 74. Light and variable wind.

    High: 74 °F

    Sunny

  • Friday Night

    Friday Night: A 20 percent chance of showers before 1am. Partly cloudy, with a low around 56. Calm wind.

    Low: 56 °F

    Slight Chance
    Showers

  • Saturday

    Saturday: Mostly sunny, with a high near 78. Calm wind becoming west northwest around 5 mph in the afternoon.

    High: 78 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 52. Calm wind.

    Low: 52 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 80. Calm wind becoming south southeast around 6 mph in the morning.

    High: 80 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 56. Light southeast wind.

    Low: 56 °F

    Mostly Clear

  • Columbus Day

    Columbus Day: Sunny, with a high near 83. Calm wind becoming south southwest around 6 mph in the morning.

    High: 83 °F

    Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 60. Light and variable wind.

    Low: 60 °F

    Partly Cloudy

Detailed Forecast

Tonight
Clear, with a low around 42. Calm wind.
Friday
Sunny, with a high near 74. Light and variable wind.
Friday Night
A 20 percent chance of showers before 1am. Partly cloudy, with a low around 56. Calm wind.
Saturday
Mostly sunny, with a high near 78. Calm wind becoming west northwest around 5 mph in the afternoon.
Saturday Night
Mostly clear, with a low around 52. Calm wind.
Sunday
Sunny, with a high near 80. Calm wind becoming south southeast around 6 mph in the morning.
Sunday Night
Mostly clear, with a low around 56. Light southeast wind.
Columbus Day
Sunny, with a high near 83. Calm wind becoming south southwest around 6 mph in the morning.
Monday Night
Partly cloudy, with a low around 60. Light and variable wind.
Tuesday
Mostly sunny, with a high near 79. North wind 3 to 7 mph.
Tuesday Night
Partly cloudy, with a low around 57. North wind around 5 mph becoming calm in the evening.
Wednesday
Sunny, with a high near 78. North northeast wind 3 to 7 mph.
Wednesday Night
Mostly clear, with a low around 53. Light east wind.
Thursday
Sunny, with a high near 78. Light and variable wind becoming south southeast 5 to 8 mph in the morning.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Johnston City IL
 37.82°N 88.91°W
Last Update:
10:01 pm CDT Oct 9, 2025
Forecast Valid:
10pm CDT Oct 9, 2025-6pm CDT Oct 16, 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