Normally I would say that California has some of the best flying weather in the country.
However, this year there are SO MANY wild fires/forest fires I would be very careful.
Flying on the pacific coast would be good, but summertime there can be what is called, "a marine layer" which is fog and can delay things.
What part of California are you willing to go to? The interior I would stay away from right now. I would look at Paso Robles, south to the coast down to Camarillo.