| National Weather Service Forecast for:
Crystal Lake IL Issued by: National Weather Service Chicago, IL |
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| Updated: 3:51 am CDT Aug 20, 2026 | ||||||||||||||||||
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| Today |
Patchy fog before 8am. Otherwise, sunny, with a high near 79. Calm wind becoming northeast around 5 mph. |
| Tonight |
Partly cloudy, with a low around 59. Calm wind becoming south southwest around 5 mph. |
| Friday |
A 50 percent chance of showers and thunderstorms, mainly after 1pm. Mostly cloudy, with a high near 79. South southwest wind 5 to 10 mph, with gusts as high as 15 mph. |
| Friday Night |
A 40 percent chance of showers and thunderstorms before 1am. Mostly cloudy, then gradually becoming mostly clear, with a low around 62. Southwest wind around 5 mph becoming west northwest after midnight. Winds could gust as high as 10 mph. |
| Saturday |
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 77. Northwest wind 5 to 10 mph, with gusts as high as 20 mph. |
| Saturday Night |
Mostly clear, with a low around 58. |
| Sunday |
Sunny, with a high near 75. |
| 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 78. |
| Tuesday Night |
Partly cloudy, with a low around 63. |
| Wednesday |
Mostly sunny, with a high near 79. |
Forecast from NOAA-NWS for Crystal Lake IL.
