Thunderstorms and Heavy Rain in the Mid-South; Heat Continues in the Southeast and Southwest

Severe thunderstorms and heavy rain are expected across portions of the mid-Mississippi Valley into the Ohio Valley and portions of Arizona. Dangerous heat persists in the South and Southeast while building into the Southwest. Overnight lows will be so warm that, when combined with oppressive dew points, little-to-no relief from the scorching daytime highs will be available. Read More >

Hazardous Weather Conditions

Current conditions at

Chicago/Waukegan Regional Airport (KUGN)

Lat: 42.43°NLon: 87.86°WElev: 709ft.

Fair

64°F

18°C

Humidity 96%
Wind Speed W 3 mph
Barometer 29.92 in (1012.1 mb)
Dewpoint 63°F (17°C)
Visibility 10.00 mi
Last update 19 Aug 2:51 am CDT
Extended Forecast for

McHenry IL

  • Overnight

    Overnight: Areas of fog.  Otherwise, mostly cloudy, with a low around 62. West wind around 5 mph.

    Low: 62 °F

    Areas Fog

  • Wednesday

    Wednesday: A 20 percent chance of showers after 2pm.  Areas of fog before 9am.  Otherwise, partly sunny, with a high near 79. North northwest wind around 5 mph becoming northeast in the afternoon.

    High: 79 °F

    Areas Fog
    then Slight
    Chance
    Showers

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 58. East northeast wind around 5 mph becoming northwest after midnight.

    Low: 58 °F

    Partly Cloudy

  • Thursday

    Thursday: Sunny, with a high near 80. Calm wind becoming southeast around 5 mph in the afternoon.

    High: 80 °F

    Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 60. Southeast wind around 5 mph becoming south southwest after midnight.

    Low: 60 °F

    Partly Cloudy

  • Friday

    Friday: A 40 percent chance of showers and thunderstorms.  Partly sunny, with a high near 78.

    High: 78 °F

    Chance
    Showers

  • Friday Night

    Friday Night: A 20 percent chance of showers and thunderstorms before 1am.  Partly cloudy, with a low around 62.

    Low: 62 °F

    Slight Chance
    T-storms

  • Saturday

    Saturday: Mostly sunny, with a high near 79.

    High: 79 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 58.

    Low: 58 °F

    Mostly Clear

Detailed Forecast

Overnight
Areas of fog. Otherwise, mostly cloudy, with a low around 62. West wind around 5 mph.
Wednesday
A 20 percent chance of showers after 2pm. Areas of fog before 9am. Otherwise, partly sunny, with a high near 79. North northwest wind around 5 mph becoming northeast in the afternoon.
Wednesday Night
Partly cloudy, with a low around 58. East northeast wind around 5 mph becoming northwest after midnight.
Thursday
Sunny, with a high near 80. Calm wind becoming southeast around 5 mph in the afternoon.
Thursday Night
Partly cloudy, with a low around 60. Southeast wind around 5 mph becoming south southwest after midnight.
Friday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 78.
Friday Night
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 62.
Saturday
Mostly sunny, with a high near 79.
Saturday Night
Mostly clear, with a low around 58.
Sunday
Mostly sunny, with a high near 76.
Sunday Night
Partly cloudy, with a low around 56.
Monday
Mostly sunny, with a high near 76.
Monday Night
Partly cloudy, with a low around 59.
Tuesday
Mostly sunny, with a high near 79.
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ABOUT THIS FORECAST

 
Point Forecast:
McHenry IL
 42.34°N 88.26°W
3:01 am CDT Aug 19, 2026
3am CDT Aug 19, 2026-6pm CDT Aug 25, 2026
 
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Additional Resources

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Hourly Weather Forecast

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