HTTP/1.1 200 OK Server: Apache X-Content-Type-Options: nosniff X-XSS-Protection: 1; mode=block Content-Security-Policy: default-src 'none'; style-src 'self' code.jquery.com *.arcgis.com cdn.jsdelivr.net 'unsafe-inline'; script-src-elem 'self' cdn.gov.cfigroup.com *.digitalgov.gov *.google-analytics.com *.arcgis.com code.jquery.com www.googletagmanager.com s.go-mpulse.net 'unsafe-inline'; img-src 'self' data: *.ncep.noaa.gov *.noaa.gov *.weather.gov *.arcgisonline.com *.arcgis.com maps.google.com; connect-src 'self' *.google-analytics.com *.arcgis.com opengeo.ncep.noaa.gov *.weather.gov; font-src 'self' cdn.jsdelivr.net; script-src 'unsafe-eval' 'unsafe-inline' Referrer-Policy: strict-origin-when-cross-origin Strict-Transport-Security: max-age=31536000; includeSubdomains; preload; Access-Control-Allow-Origin: * Content-Type: text/html; charset=UTF-8 Cache-Control: max-age=899 Expires: Tue, 30 Jun 2026 08:54:24 GMT Date: Tue, 30 Jun 2026 08:39:25 GMT Content-Length: 27842 Connection: keep-alive National Weather Service
National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
7-Day Forecast 42.23°N 88.33°W (Text-Only)
NWS Forecast for: Crystal Lake IL
Issued by: National Weather Service Chicago, IL
Last Update: 2:41 am CDT Jun 30, 2026		Print

  • Overnight

    Overnight: Partly cloudy, with a low around 77. South southwest wind around 10 mph, with gusts as high as 20 mph.

    Low: 77 °F

    Partly Cloudy



  • Tuesday

    Tuesday: Mostly sunny, with a high near 92. Heat index values as high as 104. Southwest wind 10 to 15 mph, with gusts as high as 30 mph.

    High: 92 °F

    Mostly Sunny



  • Tuesday
    Night

    Tuesday Night: Mostly clear, with a low around 76. Southwest wind 10 to 15 mph, with gusts as high as 30 mph.

    Low: 76 °F

    Mostly Clear



  • Wednesday

    Wednesday: Sunny, with a high near 94. Heat index values as high as 105. Southwest wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 94 °F

    Sunny



  • Wednesday
    Night

    Wednesday Night: Mostly clear, with a low around 77. South southwest wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 77 °F

    Mostly Clear



  • Thursday

    Thursday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92.

    High: 92 °F

    Sunny then
    Slight Chance
    T-storms

  • Thursday
    Night

    Thursday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Partly cloudy, with a low around 73. Chance of precipitation is 60%.

    Low: 73 °F

    Chance
    T-storms then
    Showers
    Likely

  • Friday

    Friday: Showers likely, with thunderstorms also possible after 1pm. Partly sunny, with a high near 90.

    High: 90 °F

    Showers
    Likely


  • Friday
    Night

    Friday Night: Showers likely and possibly a thunderstorm before 1am. Partly cloudy, with a low around 70.

    Low: 70 °F

    Showers
    Likely




    • Overnight: Partly cloudy, with a low around 77. South southwest wind around 10 mph, with gusts as high as 20 mph.

    Tuesday: Mostly sunny, with a high near 92. Heat index values as high as 104. Southwest wind 10 to 15 mph, with gusts as high as 30 mph.

    Tuesday Night: Mostly clear, with a low around 76. Southwest wind 10 to 15 mph, with gusts as high as 30 mph.

    Wednesday: Sunny, with a high near 94. Heat index values as high as 105. Southwest wind 10 to 15 mph, with gusts as high as 25 mph.

    Wednesday Night: Mostly clear, with a low around 77. South southwest wind 10 to 15 mph, with gusts as high as 25 mph.

    Thursday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92.

    Thursday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Partly cloudy, with a low around 73. Chance of precipitation is 60%.

    Friday: Showers likely, with thunderstorms also possible after 1pm. Partly sunny, with a high near 90.

    Friday Night: Showers likely and possibly a thunderstorm before 1am. Partly cloudy, with a low around 70.

    Independence Day: A chance of showers, with thunderstorms also possible after 1pm. Partly sunny, with a high near 87.

    Saturday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 67.

    Sunday: A chance of showers and thunderstorms. Partly sunny, with a high near 86.

    Sunday Night: Partly cloudy, with a low around 65.

    Monday: Mostly sunny, with a high near 84.


    Crystal Lake IL
     42.23°N 88.33°W

    Visit your local NWS office at: https://www.weather.gov/lot