National Weather Service Forecast for: Lake Forest CA
Issued by: National Weather Service San Diego, CA
Updated: 12:05 pm PDT Jul 12, 2026
 
Tonight

Tonight: Partly cloudy, with a low around 65. West wind around 5 mph becoming calm  in the evening.
Partly Cloudy
Monday

Monday: Partly sunny, with a high near 85. Calm wind becoming west around 5 mph in the afternoon.
Partly Sunny
Monday
Night
Monday Night: Partly cloudy, with a low around 67. West wind around 5 mph becoming calm  in the evening.
Partly Cloudy
Tuesday

Tuesday: Mostly sunny, with a high near 89. Light west wind increasing to 5 to 10 mph in the afternoon.
Mostly Sunny
Tuesday
Night
Tuesday Night: Partly cloudy, with a low around 70. West wind around 5 mph becoming calm  in the evening.
Partly Cloudy
Wednesday

Wednesday: Sunny, with a high near 96.
Sunny
Wednesday
Night
Wednesday Night: Mostly clear, with a low around 72.
Mostly Clear
Thursday

Thursday: Mostly sunny, with a high near 90.
Mostly Sunny
Thursday
Night
Thursday Night: Partly cloudy, with a low around 68.
Partly Cloudy
Lo 65 °F Hi 85 °F Lo 67 °F Hi 89 °F Lo 70 °F Hi 96 °F Lo 72 °F Hi 90 °F Lo 68 °F

Extreme Heat Watch
 

Tonight
 
Partly cloudy, with a low around 65. West wind around 5 mph becoming calm in the evening.
Monday
 
Partly sunny, with a high near 85. Calm wind becoming west around 5 mph in the afternoon.
Monday Night
 
Partly cloudy, with a low around 67. West wind around 5 mph becoming calm in the evening.
Tuesday
 
Mostly sunny, with a high near 89. Light west wind increasing to 5 to 10 mph in the afternoon.
Tuesday Night
 
Partly cloudy, with a low around 70. West wind around 5 mph becoming calm in the evening.
Wednesday
 
Sunny, with a high near 96.
Wednesday Night
 
Mostly clear, with a low around 72.
Thursday
 
Mostly sunny, with a high near 90.
Thursday Night
 
Partly cloudy, with a low around 68.
Friday
 
A slight chance of showers after 11am. Mostly sunny, with a high near 86.
Friday Night
 
A slight chance of showers. Partly cloudy, with a low around 68.
Saturday
 
A slight chance of showers. Mostly sunny, with a high near 87.
Saturday Night
 
Partly cloudy, with a low around 67.
Sunday
 
Mostly sunny, with a high near 85.

 

Forecast from NOAA-NWS for Lake Forest CA.