Decide what region of the state you will visit. Are you going to the beach to surf? Do you want to star search in Hollywood? Do you want to hike in the redwood forest? Knowing ahead of time where in the state you are going and what you want to do will help you to take the necessary items. Each region of California follows a general weather pattern that you can use a guide when packing.
Choose clothes wisely. California's erratic temperatures mean that you may be roasting during the day and then need at sweater a night when temperatures drop. Pack a variety of clothes that can be layered, such as sweaters and a light jacket. Don't worry about bringing a suit and tie if traveling for business in places such as San Diego and Los Angeles as the style is very casual, even for business meetings.
Bring walking shoes and sandals. A pair of good walking shoes is essential as you will probably walk a lot around California's varied terrain. But sandals can be worn throughout the year in San Diego and Los Angeles, where the climate is temperate and the dress style is laid back, and can be just as comfortable for sightseeing.
Bring your swimsuit and sunscreen. California's winters are generally too cold to swim but summers are warm enough to swim in both the Pacific ocean and a hotel's pool. Sunscreen is needed throughout the year, especially if you will be spending a lot of time outside.
Bring a heavy jacket if traveling to the mountains or higher altitudes in the winter. It does snow in California, and the temperatures can be quite chilly.
