NWS Forecast for Crystal Lake IL

National Weather Service Forecast for: Crystal Lake IL
Issued by: National Weather Service Chicago, IL

Updated: 4:46 am CST Dec 5, 2025

Today Mostly Cloudy	Tonight Patchy Wintry Mix	Saturday Partly Sunny	Saturday Night Slight Chance Snow then Snow	Sunday Chance Snow then Mostly Sunny	Sunday Night Slight Chance Snow Showers then Mostly Cloudy	Monday Partly Sunny	Monday Night Chance Snow	Tuesday Mostly Cloudy then Chance Snow
Hi 25 °F	Lo 21 °F	Hi 24 °F⇓	Lo 13 °F	Hi 23 °F	Lo 4 °F	Hi 20 °F	Lo 12 °F	Hi 34 °F

Hazardous Weather Outlook
Hydrologic Outlook

Today	Mostly cloudy, with a high near 25. Wind chill values as low as -7. South southwest wind 10 to 15 mph, with gusts as high as 25 mph.
Tonight	Patchy snow and freezing rain before 3am. Mostly cloudy, with a low around 21. Southwest wind 10 to 15 mph becoming west northwest after midnight. Winds could gust as high as 25 mph. Chance of precipitation is 30%.
Saturday	Partly sunny, with a temperature falling to around 19 by 5pm. West northwest wind 5 to 10 mph becoming light and variable in the afternoon.
Saturday Night	Snow, mainly after midnight. Low around 13. Calm wind becoming north around 5 mph after midnight. Winds could gust as high as 10 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 3 inches possible.
Sunday	A 50 percent chance of snow before noon. Partly sunny, with a high near 23. North wind 5 to 10 mph, with gusts as high as 20 mph.
Sunday Night	A 20 percent chance of snow showers before midnight. Mostly cloudy, with a low around 4.
Monday	Partly sunny, with a high near 20.
Monday Night	A chance of snow. Mostly cloudy, with a low around 12.
Tuesday	A chance of snow after noon. Mostly cloudy, with a high near 34.
Tuesday Night	Snow. Cloudy, with a low around 28.
Wednesday	A chance of rain and snow. Cloudy, with a high near 34.
Wednesday Night	A chance of snow. Mostly cloudy, with a low around 10.
Thursday	Partly sunny, with a high near 20.

Forecast from NOAA-NWS for Crystal Lake IL.