National Weather Service Forecast for: Crystal Lake IL
Issued by: National Weather Service Chicago, IL
Updated: 9:26 pm CDT Jun 18, 2026
 
Tonight

Tonight: Mostly clear, with a low around 54. West wind around 5 mph.
Mostly Clear

 Juneteenth

Juneteenth: Sunny, with a high near 75. West northwest wind 5 to 10 mph, with gusts as high as 15 mph.
Sunny

 Friday
Night
Friday Night: A 40 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 57. West southwest wind around 5 mph, with gusts as high as 15 mph.
Chance
Showers

 Saturday

Saturday: Sunny, with a high near 78. West wind 5 to 10 mph, with gusts as high as 20 mph.
Sunny

 Saturday
Night
Saturday Night: Partly cloudy, with a low around 57. Northwest wind around 5 mph becoming calm in the evening. Winds could gust as high as 10 mph.
Partly Cloudy

 Sunday

Sunday: A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 72. Chance of precipitation is 70%.
Chance
Showers then
Showers
Likely
 Sunday
Night
Sunday Night: Showers likely and possibly a thunderstorm before 1am, then a chance of showers. Mostly cloudy, with a low around 55. Chance of precipitation is 60%.
Showers
Likely

 Monday

Monday: Mostly sunny, with a high near 73.
Mostly Sunny

 Monday
Night
Monday Night: Mostly clear, with a low around 52.
Mostly Clear
Lo 54 °F Hi 75 °F Lo 57 °F Hi 78 °F Lo 57 °F Hi 72 °F Lo 55 °F Hi 73 °F Lo 52 °F

 

Tonight
 
 Mostly clear, with a low around 54. West wind around 5 mph.
Juneteenth
 
 Sunny, with a high near 75. West northwest wind 5 to 10 mph, with gusts as high as 15 mph.
Friday Night
 
 A 40 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 57. West southwest wind around 5 mph, with gusts as high as 15 mph.
Saturday
 
 Sunny, with a high near 78. West wind 5 to 10 mph, with gusts as high as 20 mph.
Saturday Night
 
 Partly cloudy, with a low around 57. Northwest wind around 5 mph becoming calm in the evening. Winds could gust as high as 10 mph.
Sunday
 
 A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 72. Chance of precipitation is 70%.
Sunday Night
 
 Showers likely and possibly a thunderstorm before 1am, then a chance of showers. Mostly cloudy, with a low around 55. Chance of precipitation is 60%.
Monday
 
 Mostly sunny, with a high near 73.
Monday Night
 
 Mostly clear, with a low around 52.
Tuesday
 
 Mostly sunny, with a high near 75.
Tuesday Night
 
 A chance of showers. Partly cloudy, with a low around 56.
Wednesday
 
 A chance of showers. Partly sunny, with a high near 75.
Wednesday Night
 
 A chance of showers. Partly cloudy, with a low around 56.
Thursday
 
 Mostly sunny, with a high near 76.

 

Forecast from NOAA-NWS for Crystal Lake IL.