National Weather Service Forecast for: Crystal Lake IL
Issued by: National Weather Service Chicago, IL
Updated: 9:36 am CDT Oct 6, 2026
 
This
Afternoon
This Afternoon: Sunny, with a high near 72. South southwest wind around 15 mph, with gusts as high as 30 mph.
Sunny
 Tonight

Tonight: Partly cloudy, with a low around 54. South southwest wind around 10 mph, with gusts as high as 20 mph.
Partly Cloudy
 Wednesday

Wednesday: Mostly sunny, with a high near 74. West northwest wind 5 to 10 mph, with gusts as high as 15 mph.
Mostly Sunny
 Wednesday
Night
Wednesday Night: Mostly clear during the early evening, then becoming mostly cloudy, with a low around 48. West northwest wind around 5 mph, with gusts as high as 10 mph.
Mostly Cloudy
 Thursday

Thursday: Mostly sunny, with a high near 67. Northwest wind 5 to 10 mph.
Mostly Sunny
 Thursday
Night
Thursday Night: Mostly clear, with a low around 44.
Mostly Clear
 Friday

Friday: Sunny, with a high near 69.
Sunny
 Friday
Night
Friday Night: Mostly clear, with a low around 51.
Mostly Clear
 Saturday

Saturday: Sunny, with a high near 76.
Sunny
Hi 72 °F Lo 54 °F Hi 74 °F Lo 48 °F Hi 67 °F Lo 44 °F Hi 69 °F Lo 51 °F Hi 76 °F

 

This Afternoon
 
 Sunny, with a high near 72. South southwest wind around 15 mph, with gusts as high as 30 mph.
Tonight
 
 Partly cloudy, with a low around 54. South southwest wind around 10 mph, with gusts as high as 20 mph.
Wednesday
 
 Mostly sunny, with a high near 74. West northwest wind 5 to 10 mph, with gusts as high as 15 mph.
Wednesday Night
 
 Mostly clear during the early evening, then becoming mostly cloudy, with a low around 48. West northwest wind around 5 mph, with gusts as high as 10 mph.
Thursday
 
 Mostly sunny, with a high near 67. Northwest wind 5 to 10 mph.
Thursday Night
 
 Mostly clear, with a low around 44.
Friday
 
 Sunny, with a high near 69.
Friday Night
 
 Mostly clear, with a low around 51.
Saturday
 
 Sunny, with a high near 76.
Saturday Night
 
 Partly cloudy, with a low around 57.
Sunday
 
 Mostly sunny, with a high near 78.
Sunday Night
 
 Partly cloudy, with a low around 54.
Columbus Day
 
 Mostly sunny, with a high near 72.

 

Forecast from NOAA-NWS for Crystal Lake IL.