I'm with Frederick: How about both?
I'd suggest Anza Borrego State Park for a couple of days before motoring into San Diego for a cruise. You could soak up warm, dry sun and get some exercise (hiking) and solitude before cruising the Baja Coast. (I prefer the southern Tamarisk Grove camping ground to the main one. No hookups but quiet and shaded.)
If you (or your lovely Other) prefer a hotel, consider the Palm Springs/Palm Desert/etc. area. It's very nice then, warm but not hot, sunny and dry.
Wherever you go, have fun!