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

21°F

-6°C

Humidity 86%
Wind Speed N 12 mph
Barometer 30.36 in
Dewpoint 18°F (-8°C)
Visibility 10.00 mi
Wind Chill9°F (-13°C)
Last update 4 Feb 7:47 am CST
Extended Forecast for

Johnston City IL

  • Today

    Today: Partly sunny, with a high near 32. North wind 7 to 10 mph.

    High: 32 °F

    Partly Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 14. North wind 5 to 7 mph becoming calm in the evening.

    Low: 14 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly cloudy, with a high near 35. Calm wind becoming south southwest 5 to 8 mph in the afternoon.

    High: 35 °F

    Mostly Cloudy

  • Thursday Night

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

    Low: 29 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 50. West southwest wind 6 to 13 mph becoming north northwest in the afternoon. Winds could gust as high as 20 mph.

    High: 50 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 26. North northwest wind 5 to 7 mph.

    Low: 26 °F

    Partly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 42. North northeast wind around 6 mph becoming east southeast in the afternoon.

    High: 42 °F

    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 28. South southeast wind 3 to 6 mph.

    Low: 28 °F

    Partly Cloudy

  • Sunday

    Sunday: Mostly sunny, with a high near 51. South wind 5 to 8 mph becoming north in the afternoon.

    High: 51 °F

    Mostly Sunny

Detailed Forecast

Today
Partly sunny, with a high near 32. North wind 7 to 10 mph.
Tonight
Partly cloudy, with a low around 14. North wind 5 to 7 mph becoming calm in the evening.
Thursday
Mostly cloudy, with a high near 35. Calm wind becoming south southwest 5 to 8 mph in the afternoon.
Thursday Night
Partly cloudy, with a low around 29. West southwest wind 6 to 8 mph.
Friday
Mostly sunny, with a high near 50. West southwest wind 6 to 13 mph becoming north northwest in the afternoon. Winds could gust as high as 20 mph.
Friday Night
Partly cloudy, with a low around 26. North northwest wind 5 to 7 mph.
Saturday
Sunny, with a high near 42. North northeast wind around 6 mph becoming east southeast in the afternoon.
Saturday Night
Partly cloudy, with a low around 28. South southeast wind 3 to 6 mph.
Sunday
Mostly sunny, with a high near 51. South wind 5 to 8 mph becoming north in the afternoon.
Sunday Night
Partly cloudy, with a low around 29. Light north northeast wind.
Monday
Mostly sunny, with a high near 50. Calm wind becoming south southwest around 6 mph in the afternoon.
Monday Night
Mostly cloudy, with a low around 37. South wind 3 to 6 mph.
Tuesday
A slight chance of showers. Partly sunny, with a high near 58. South wind 6 to 9 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:
7:52 am CST Feb 4, 2026
Forecast Valid:
8am CST Feb 4, 2026-6pm CST Feb 10, 2026
 
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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