The weather in California varies greatly depending on which part of the state you are visiting. In general, the northern part of the state has cooler temperatures and more rainfall than the southern part of the state. The best time to visit California depends on your travel plans and preferences. For example, if you want to go surfing or spend time at the beach, you should plan your trip for the summer when temperatures are warm and sea conditions are ideal. If you want to ski or snowboard, however, you should visit in the winter when there is snow at mountaintops throughout the state.