National Weather Service Forecast for: Lake Forest CA
Issued by: National Weather Service San Diego, CA
Updated: 12:18 am PDT Sep 13, 2026
 
Overnight

Overnight: Mostly cloudy, with a low around 66. Calm wind.
Mostly Cloudy
Sunday

Sunday: Partly sunny, then gradually becoming sunny, with a high near 85. Calm wind becoming southwest around 5 mph in the afternoon.
Becoming
Sunny
Sunday
Night
Sunday Night: Increasing clouds, with a low around 64. Calm wind becoming southeast around 5 mph after midnight.
Increasing
Clouds
Monday

Monday: Partly sunny, then gradually becoming sunny, with a high near 83. South wind 5 to 10 mph.
Becoming
Sunny
Monday
Night
Monday Night: Mostly clear, with a low around 63. Southeast wind around 5 mph.
Mostly Clear
Tuesday

Tuesday: Sunny, with a high near 82.
Sunny
Tuesday
Night
Tuesday Night: Partly cloudy, with a low around 61.
Partly Cloudy
Wednesday

Wednesday: Sunny, with a high near 83.
Sunny
Wednesday
Night
Wednesday Night: Mostly clear, with a low around 61.
Mostly Clear
Lo 66 °F Hi 85 °F Lo 64 °F Hi 83 °F Lo 63 °F Hi 82 °F Lo 61 °F Hi 83 °F Lo 61 °F

 

Overnight
 
Mostly cloudy, with a low around 66. Calm wind.
Sunday
 
Partly sunny, then gradually becoming sunny, with a high near 85. Calm wind becoming southwest around 5 mph in the afternoon.
Sunday Night
 
Increasing clouds, with a low around 64. Calm wind becoming southeast around 5 mph after midnight.
Monday
 
Partly sunny, then gradually becoming sunny, with a high near 83. South wind 5 to 10 mph.
Monday Night
 
Mostly clear, with a low around 63. Southeast wind around 5 mph.
Tuesday
 
Sunny, with a high near 82.
Tuesday Night
 
Partly cloudy, with a low around 61.
Wednesday
 
Sunny, with a high near 83.
Wednesday Night
 
Mostly clear, with a low around 61.
Thursday
 
Sunny, with a high near 84.
Thursday Night
 
Clear, with a low around 63.
Friday
 
Sunny, with a high near 88.
Friday Night
 
Clear, with a low around 66.
Saturday
 
Sunny, with a high near 91.

 

Forecast from NOAA-NWS for Lake Forest CA.