National Weather Service Forecast for: Crystal Lake IL
Issued by: National Weather Service Chicago, IL
Updated: 3:01 am CDT Jun 22, 2026
 
Today

Today: Mostly sunny, with a high near 73. North northeast wind around 10 mph, with gusts as high as 15 mph.
Mostly Sunny

 Tonight

Tonight: Mostly clear, with a low around 51. North northeast wind 5 to 10 mph, with gusts as high as 15 mph.
Mostly Clear

 Tuesday

Tuesday: Increasing clouds, with a high near 74. Calm wind becoming east northeast around 5 mph.
Increasing
Clouds

 Tuesday
Night
Tuesday Night: Mostly cloudy, with a low around 57. East southeast wind around 5 mph becoming south after midnight. Winds could gust as high as 10 mph.
Mostly Cloudy

 Wednesday

Wednesday: A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 77. South southwest wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%.
Chance
Showers then
Showers
Likely
 Wednesday
Night
Wednesday Night: A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 1am. Partly cloudy, with a low around 58. Chance of precipitation is 40%.
Chance
T-storms then
Chance
Showers
 Thursday

Thursday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 76.
Mostly Sunny
then Slight
Chance
T-storms
 Thursday
Night
Thursday Night: Partly cloudy, with a low around 56.
Partly Cloudy

 Friday

Friday: Mostly sunny, with a high near 77.
Mostly Sunny
Hi 73 °F Lo 51 °F Hi 74 °F Lo 57 °F Hi 77 °F Lo 58 °F Hi 76 °F Lo 56 °F Hi 77 °F

Hazardous Weather Outlook
 

Today
 
 Mostly sunny, with a high near 73. North northeast wind around 10 mph, with gusts as high as 15 mph.
Tonight
 
 Mostly clear, with a low around 51. North northeast wind 5 to 10 mph, with gusts as high as 15 mph.
Tuesday
 
 Increasing clouds, with a high near 74. Calm wind becoming east northeast around 5 mph.
Tuesday Night
 
 Mostly cloudy, with a low around 57. East southeast wind around 5 mph becoming south after midnight. Winds could gust as high as 10 mph.
Wednesday
 
 A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 77. South southwest wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%.
Wednesday Night
 
 A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 1am. Partly cloudy, with a low around 58. Chance of precipitation is 40%.
Thursday
 
 A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 76.
Thursday Night
 
 Partly cloudy, with a low around 56.
Friday
 
 Mostly sunny, with a high near 77.
Friday Night
 
 Mostly cloudy, with a low around 58.
Saturday
 
 Partly sunny, with a high near 80.
Saturday Night
 
 A chance of showers. Mostly cloudy, with a low around 64.
Sunday
 
 Mostly sunny, with a high near 86.

 

Forecast from NOAA-NWS for Crystal Lake IL.