National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

Marion - Williamson County Regional Airport (KMWA)

Lat: 37.77°NLon: 89.01°WElev: 486ft.

Mostly Cloudy

75°F

24°C

Humidity 83%
Wind Speed Calm
Barometer 30.04 in
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Last update 15 Jun 9:45 am CDT
Extended Forecast for

Johnston City IL

  • Today

    Today: Partly sunny, with a high near 84. North northwest wind 3 to 5 mph.

    High: 84 °F

    Partly Sunny

  • Tonight

    Tonight: Mostly cloudy, with a low around 70. Light and variable wind.

    Low: 70 °F

    Mostly Cloudy

  • Monday

    Monday: A 50 percent chance of showers and thunderstorms, mainly after 7am. Mostly cloudy, with a high near 81. Calm wind becoming southeast around 5 mph in the afternoon.

    High: 81 °F

    Chance
    Showers then
    Chance
    T-storms

  • Monday Night

    Monday Night: A slight chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 1am. Mostly cloudy, with a low around 70. Light and variable wind. Chance of precipitation is 20%.

    Low: 70 °F

    Slight Chance
    T-storms then
    Slight Chance
    Showers

  • Tuesday

    Tuesday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 88. South southwest wind 3 to 8 mph.

    High: 88 °F

    Partly Sunny
    then Slight
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 74. South wind 6 to 8 mph.

    Low: 74 °F

    Mostly Clear
    then Slight
    Chance
    T-storms

  • Wednesday

    Wednesday: A 50 percent chance of showers and thunderstorms, mainly after 1pm. Partly sunny, with a high near 87. Southwest wind 10 to 14 mph, with gusts as high as 22 mph.

    High: 87 °F

    Slight Chance
    T-storms then
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 71. Southwest wind 6 to 10 mph, with gusts as high as 18 mph.

    Low: 71 °F

    Chance
    T-storms

  • Juneteenth

    Juneteenth: A chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 86. West wind around 6 mph.

    High: 86 °F

    Partly Sunny
    then Chance
    T-storms

Detailed Forecast

Today
Partly sunny, with a high near 84. North northwest wind 3 to 5 mph.
Tonight
Mostly cloudy, with a low around 70. Light and variable wind.
Monday
A 50 percent chance of showers and thunderstorms, mainly after 7am. Mostly cloudy, with a high near 81. Calm wind becoming southeast around 5 mph in the afternoon.
Monday Night
A slight chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 1am. Mostly cloudy, with a low around 70. Light and variable wind. Chance of precipitation is 20%.
Tuesday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 88. South southwest wind 3 to 8 mph.
Tuesday Night
A 20 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 74. South wind 6 to 8 mph.
Wednesday
A 50 percent chance of showers and thunderstorms, mainly after 1pm. Partly sunny, with a high near 87. Southwest wind 10 to 14 mph, with gusts as high as 22 mph.
Wednesday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 71. Southwest wind 6 to 10 mph, with gusts as high as 18 mph.
Juneteenth
A chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 86. West wind around 6 mph.
Thursday Night
Mostly clear, with a low around 68. Calm wind.
Friday
Sunny, with a high near 90. Calm wind becoming south southwest 5 to 7 mph in the afternoon.
Friday Night
Mostly clear, with a low around 73. South wind around 6 mph.
Saturday
Sunny, with a high near 92. South southwest wind 6 to 10 mph.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Johnston City IL
 37.82°N 88.94°W
Last Update:
9:18 am CDT Jun 15, 2025
Forecast Valid:
10am CDT Jun 15, 2025-6pm CDT Jun 21, 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