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

Hazardous Weather Conditions

Current conditions at

Chicago/Waukegan Regional Airport (KUGN)

Lat: 42.43°NLon: 87.86°WElev: 709ft.

Fog/Mist

70°F

21°C

Humidity 100%
Wind Speed S 3 mph
Barometer 29.85 in (1009.7 mb)
Dewpoint 70°F (21°C)
Visibility 5.00 mi
Last update 12 Aug 12:51 am CDT
Extended Forecast for

Grayslake IL

  • Overnight

    Overnight: A 20 percent chance of showers and thunderstorms. Areas of fog. Otherwise, mostly cloudy, with a low around 68. Calm wind.

    Low: 68 °F

    Slight Chance
    T-storms and
    Areas Fog

  • Wednesday

    Wednesday: A 30 percent chance of showers and thunderstorms, mainly before 2pm. Areas of fog before 9am. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 82. Light and variable wind becoming southwest 5 to 10 mph in the afternoon.

    High: 82 °F

    Chance
    T-storms and
    Areas Fog

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 67. Northeast wind around 5 mph becoming calm in the evening.

    Low: 67 °F

    Mostly Cloudy

  • Thursday

    Thursday: A chance of showers, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 78. East wind around 5 mph. Chance of precipitation is 50%.

    High: 78 °F

    Chance
    Showers then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 66. East wind around 5 mph, with gusts as high as 10 mph. Chance of precipitation is 40%.

    Low: 66 °F

    Chance
    Showers

  • Friday

    Friday: Partly sunny, with a high near 78.

    High: 78 °F

    Partly Sunny

  • Friday Night

    Friday Night: A slight chance of showers, then a chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 66. Chance of precipitation is 50%.

    Low: 66 °F

    Slight Chance
    Showers then
    Chance
    Showers

  • Saturday

    Saturday: Showers likely and possibly a thunderstorm before 1pm. Mostly cloudy, with a high near 81.

    High: 81 °F

    Showers
    Likely

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 69.

    Low: 69 °F

    Chance
    T-storms then
    Showers
    Likely

Detailed Forecast

Overnight
A 20 percent chance of showers and thunderstorms. Areas of fog. Otherwise, mostly cloudy, with a low around 68. Calm wind.
Wednesday
A 30 percent chance of showers and thunderstorms, mainly before 2pm. Areas of fog before 9am. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 82. Light and variable wind becoming southwest 5 to 10 mph in the afternoon.
Wednesday Night
Mostly cloudy, with a low around 67. Northeast wind around 5 mph becoming calm in the evening.
Thursday
A chance of showers, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 78. East wind around 5 mph. Chance of precipitation is 50%.
Thursday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 66. East wind around 5 mph, with gusts as high as 10 mph. Chance of precipitation is 40%.
Friday
Partly sunny, with a high near 78.
Friday Night
A slight chance of showers, then a chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 66. Chance of precipitation is 50%.
Saturday
Showers likely and possibly a thunderstorm before 1pm. Mostly cloudy, with a high near 81.
Saturday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 69.
Sunday
A chance of showers and thunderstorms before 1pm. Mostly cloudy, with a high near 81.
Sunday Night
Mostly cloudy, with a low around 63.
Monday
Mostly sunny, with a high near 77.
Monday Night
Partly cloudy, with a low around 60.
Tuesday
Mostly sunny, with a high near 78.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Grayslake IL
 42.35°N 88.02°W
Last Update:
1:45 am CDT Aug 12, 2026
Forecast Valid:
1am CDT Aug 12, 2026-6pm CDT Aug 18, 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