Why is California considered as a region with a pleasant climate?

On the west coast of California, it is warm in winter and cool in summer, with plenty of sunshine, so it is very comfortable to live in it. Many cities can be used as a choice for settlement, such as Los Angeles, San Francisco, San Diego and San Jose. Even in winter, the temperature can reach 9-25 degrees.

Among them, San Diego has always been called "the best city in America" and the weather is called one of the most ideal cities in the world. With abundant sunshine all year round and mild and pleasant climate, it has become a major tourist attraction in California, USA.