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

Heavy Rainfall Across South Texas; Heat in the West

Excessive rainfall may produce locally considerable flash flooding over parts of South Texas, the western Gulf Coast, and Lower Mississippi River Valley through Thursday. Hot temperatures will persist over central and northern California and the Pacific Northwest through today. Read More >

Current conditions at

Marion - Williamson County Regional Airport (KMWA)

Lat: 37.77°NLon: 89.01°WElev: 486ft.

Partly Cloudy

58°F

14°C

Humidity 98%
Wind Speed Calm
Barometer 29.93 in
Dewpoint 58°F (14°C)
Visibility 10.00 mi
Last update 16 Jun 2:35 am CDT
Extended Forecast for

Johnston City IL

  • Overnight

    Overnight: Mostly clear, with a low around 59. Calm wind.

    Low: 59 °F

    Mostly Clear

  • Tuesday

    Tuesday: A 40 percent chance of showers and thunderstorms, mainly between 3pm and 5pm. Increasing clouds, with a high near 84. Light and variable wind becoming west southwest 6 to 11 mph in the morning. Winds could gust as high as 20 mph.

    High: 84 °F

    Sunny then
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A slight chance of showers and thunderstorms before 7pm, then a slight chance of showers between 7pm and 8pm. Partly cloudy, with a low around 61. West southwest wind 5 to 7 mph becoming calm in the evening. Chance of precipitation is 20%.

    Low: 61 °F

    Slight Chance
    T-storms then
    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 90. Breezy, with a light south wind becoming south southwest 21 to 26 mph in the morning. Winds could gust as high as 37 mph.

    High: 90 °F

    Sunny then
    Sunny and
    Breezy

  • Wednesday Night

    Wednesday Night: Showers and possibly a thunderstorm. Low around 73. Breezy, with a south southwest wind 20 to 25 mph decreasing to 13 to 18 mph after midnight. Winds could gust as high as 36 mph. Chance of precipitation is 80%.

    Low: 73 °F

    Showers and
    Breezy

  • Thursday

    Thursday: A chance of showers, with thunderstorms also possible after 1pm. Mostly sunny, with a high near 85. West southwest wind 8 to 10 mph becoming north northwest in the afternoon. Chance of precipitation is 50%.

    High: 85 °F

    Chance
    Showers then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 63. North wind around 6 mph becoming calm in the evening. Chance of precipitation is 50%.

    Low: 63 °F

    Chance
    Showers

  • Juneteenth

    Juneteenth: Sunny, with a high near 83. Calm wind becoming north 5 to 7 mph in the morning.

    High: 83 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 62. North wind around 5 mph becoming calm in the evening.

    Low: 62 °F

    Mostly Clear

Detailed Forecast

Overnight
Mostly clear, with a low around 59. Calm wind.
Tuesday
A 40 percent chance of showers and thunderstorms, mainly between 3pm and 5pm. Increasing clouds, with a high near 84. Light and variable wind becoming west southwest 6 to 11 mph in the morning. Winds could gust as high as 20 mph.
Tuesday Night
A slight chance of showers and thunderstorms before 7pm, then a slight chance of showers between 7pm and 8pm. Partly cloudy, with a low around 61. West southwest wind 5 to 7 mph becoming calm in the evening. Chance of precipitation is 20%.
Wednesday
Sunny, with a high near 90. Breezy, with a light south wind becoming south southwest 21 to 26 mph in the morning. Winds could gust as high as 37 mph.
Wednesday Night
Showers and possibly a thunderstorm. Low around 73. Breezy, with a south southwest wind 20 to 25 mph decreasing to 13 to 18 mph after midnight. Winds could gust as high as 36 mph. Chance of precipitation is 80%.
Thursday
A chance of showers, with thunderstorms also possible after 1pm. Mostly sunny, with a high near 85. West southwest wind 8 to 10 mph becoming north northwest in the afternoon. Chance of precipitation is 50%.
Thursday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 63. North wind around 6 mph becoming calm in the evening. Chance of precipitation is 50%.
Juneteenth
Sunny, with a high near 83. Calm wind becoming north 5 to 7 mph in the morning.
Friday Night
Mostly clear, with a low around 62. North wind around 5 mph becoming calm in the evening.
Saturday
Sunny, with a high near 86. Calm wind becoming south around 6 mph in the afternoon.
Saturday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 68. South southeast wind 3 to 6 mph.
Sunday
A chance of showers and thunderstorms. Partly sunny, with a high near 87. South wind 6 to 16 mph, with gusts as high as 24 mph.
Sunday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 71. South wind 10 to 14 mph, with gusts as high as 21 mph.
Monday
A chance of showers and thunderstorms. Mostly cloudy, with a high near 87. West southwest wind around 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:
1:55 am CDT Jun 16, 2026
Forecast Valid:
2am CDT Jun 16, 2026-6pm CDT Jun 22, 2026
 
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