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

63°F

17°C

Humidity 76%
Wind Speed Calm
Barometer 30.11 in
Dewpoint 55°F (13°C)
Visibility 10.00 mi
Last update 5 Oct 12:55 am CDT
Extended Forecast for

Johnston City IL

  • Overnight

    Overnight: Clear, with a low around 57. Light south southeast wind.

    Low: 57 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 85. South wind 6 to 10 mph, with gusts as high as 18 mph.

    High: 85 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 64. Southeast wind around 6 mph.

    Low: 64 °F

    Mostly Clear

  • Monday

    Monday: A chance of showers, with thunderstorms also possible after 10am. Partly sunny, with a high near 81. South wind 5 to 8 mph. Chance of precipitation is 50%.

    High: 81 °F

    Chance
    Showers then
    Chance
    T-storms

  • Monday Night

    Monday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 66. Southeast wind around 5 mph becoming calm in the evening. Chance of precipitation is 60%.

    Low: 66 °F

    Showers
    Likely

  • Tuesday

    Tuesday: Showers likely and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 78. Calm wind becoming northwest 5 to 7 mph in the afternoon. Chance of precipitation is 70%.

    High: 78 °F

    Showers
    Likely

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 57. North wind 6 to 8 mph.

    Low: 57 °F

    Slight Chance
    T-storms

  • Wednesday

    Wednesday: Mostly sunny, with a high near 74. Northeast wind 9 to 11 mph.

    High: 74 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 53. East northeast wind 5 to 7 mph.

    Low: 53 °F

    Mostly Clear

Detailed Forecast

Overnight
Clear, with a low around 57. Light south southeast wind.
Sunday
Sunny, with a high near 85. South wind 6 to 10 mph, with gusts as high as 18 mph.
Sunday Night
Mostly clear, with a low around 64. Southeast wind around 6 mph.
Monday
A chance of showers, with thunderstorms also possible after 10am. Partly sunny, with a high near 81. South wind 5 to 8 mph. Chance of precipitation is 50%.
Monday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 66. Southeast wind around 5 mph becoming calm in the evening. Chance of precipitation is 60%.
Tuesday
Showers likely and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 78. Calm wind becoming northwest 5 to 7 mph in the afternoon. Chance of precipitation is 70%.
Tuesday Night
A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 57. North wind 6 to 8 mph.
Wednesday
Mostly sunny, with a high near 74. Northeast wind 9 to 11 mph.
Wednesday Night
Mostly clear, with a low around 53. East northeast wind 5 to 7 mph.
Thursday
Sunny, with a high near 76. East northeast wind around 7 mph.
Thursday Night
Mostly clear, with a low around 51. Light east wind.
Friday
Sunny, with a high near 79. Calm wind becoming southeast 5 to 7 mph in the afternoon.
Friday Night
Mostly clear, with a low around 55. Light south southeast wind.
Saturday
Sunny, with a high near 80. Southeast wind 3 to 7 mph.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Johnston City IL
 37.82°N 88.91°W
Last Update:
1:16 am CDT Oct 5, 2025
Forecast Valid:
1am CDT Oct 5, 2025-6pm CDT Oct 11, 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