That Marine layer does indeed cover the coast a lot during a certain part of the year. I remember it well when I lived in Del Mar on 10th street, 50 yards from the beach.
It was the best place I have ever lived. If I could find the kind of house/land sf I need in that same neighborhood, I would be all over it. But I can’t so I will just have to visit. Interestingly, the house I lived in, was owned by folks who lived in RSF. Once their kids were out of the house, they sold the RSF house and moved in (and booted me and my roomate out).
I moved to CV after that. Nice, but not nearly as nice as I had before. Of course still nice enough for me to skip around singing “I live in San Diego, I live in San Diego, I live in San Diego.”