While the weather is mild at the coast, it can
get very hot just a few kilometers (or miles) inland.
So better don't go inland in summertime! Otherwise you may be forced to lie down and don't move like this cat on my picture.
In the winter, it is colder inland when it is milder at the coast.
Remember, this is sunny Southern California. 'Some Like It Hot' but take sunblock, sunglasses and a hat anyway. We stick our refillable waterbottle in the hotel ice bucket each night, ready for the next day of touristing.