Map of California

In much of California, the climate is sub-tropical. Along the coast, the climate is mild with cool summers. In the central Valley, the climate is similar to that of the Mediterranean, but it is more arid and continental, while in Los Angeles, it is mild to pleasantly warm and sunny most of the year.
In southeastern California, the climate is desert. To the east of Los Angeles, we find the Mojave desert, while to the east of San Diego, we find the Sonoran desert. From the deserts, a warm wind called Santa Ana can blow towards the coasts, especially the southern ones (see Los Angeles, San Diego). The Santa Ana winds blow more likely in autumn.
In the mountainous areas, the climate becomes colder. In the north, we find Mount Shasta and the Cascade chain. In the east, we find the Sierra Nevada, while in the southeast, we find the San Jacinto Mountains.

Sequoia in Yosemite

See also:
Central Valley of California: Sacramento, Stockton, Fresno, Bakersfield.
Parks of the Sierra Nevada: Yosemite, Sequoia National Park.
San Francisco Bay: San Francisco, Oakland, Fremont, San José
Los Angeles area:
Los Angeles metropolitan area: Los Angeles, Pasadena, Santa Ana, Irvine
Coast and islands: Channel Islands, Santa Barbara, Santa Monica
San Fernando Valley: San Fernando, Burbank
Inland hot and desert areas: San Bernardino, Riverside, Palm Springs
San Diego area: San Diego, Chula Vista

San Diego

Best Time

To visit California you can choose the spring, especially in April. In this way, you can avoid the summer heat of the inland and desert areas, but also the rains that can affect the whole state in winter, and the cold that mainly affects the mountainous areas in winter.
In autumn too, temperatures are generally acceptable, however, in the central-southern areas, the Santa Ana wind is more likely to blow.