National Weather Service Forecast for: Rancho Santa Margarita CA
Issued by: National Weather Service San Diego, CA
Updated: 12:34 am PDT Aug 20, 2026
 
Overnight

Overnight: Mostly clear, with a low around 65. Calm wind.
Mostly Clear
 Thursday

Thursday: Mostly sunny, with a high near 92. Calm wind becoming southwest around 5 mph in the afternoon.
Mostly Sunny
 Thursday
Night
Thursday Night: Partly cloudy, with a low around 64. East wind around 5 mph becoming calm.
Partly Cloudy
 Friday

Friday: Sunny, with a high near 93. Calm wind becoming southwest around 5 mph in the afternoon.
Sunny
 Friday
Night
Friday Night: Mostly clear, with a low around 65. Southwest wind around 5 mph becoming calm.
Mostly Clear
 Saturday

Saturday: Sunny, with a high near 93.
Sunny
 Saturday
Night
Saturday Night: Mostly clear, with a low around 66.
Mostly Clear
 Sunday

Sunday: Sunny, with a high near 93.
Sunny
 Sunday
Night
Sunday Night: Mostly clear, with a low around 65.
Mostly Clear
Lo 65 °F Hi 92 °F Lo 64 °F Hi 93 °F Lo 65 °F Hi 93 °F Lo 66 °F Hi 93 °F Lo 65 °F

 

Overnight
 
 Mostly clear, with a low around 65. Calm wind.
Thursday
 
 Mostly sunny, with a high near 92. Calm wind becoming southwest around 5 mph in the afternoon.
Thursday Night
 
 Partly cloudy, with a low around 64. East wind around 5 mph becoming calm.
Friday
 
 Sunny, with a high near 93. Calm wind becoming southwest around 5 mph in the afternoon.
Friday Night
 
 Mostly clear, with a low around 65. Southwest wind around 5 mph becoming calm.
Saturday
 
 Sunny, with a high near 93.
Saturday Night
 
 Mostly clear, with a low around 66.
Sunday
 
 Sunny, with a high near 93.
Sunday Night
 
 Mostly clear, with a low around 65.
Monday
 
 Sunny, with a high near 94.
Monday Night
 
 Mostly clear, with a low around 66.
Tuesday
 
 Sunny, with a high near 96.
Tuesday Night
 
 Mostly clear, with a low around 68.
Wednesday
 
 Sunny, with a high near 95.

 

Forecast from NOAA-NWS for Rancho Santa Margarita CA.