If you’re traveling to a new place, always do some basic research on what to pack. Travel guidebooks rarely give this valuable information. First stop for me is always www.weather.com. They may list the average weather patterns in the guidebook, but there’s no substitute for the 10 day weather forecast. First lesson: it does rain in Southern California. Warm beaches can get downright chilly at night. Freak storms happen. Always be wardrobe prepared!
You really can’t go wrong with lots of light layers, and some form of outer layer. I know from experience that I don’t look stylish in a cartoon-emblazoned sweatshirt. I also know that cruise ships in Tahiti can turn down the A/C in the dining room. Snow falls in London. You might have to walk much further than you originally planned due to a transportation strike. Don’t waste your precious travel time looking through shops for a “twin” of something you have at home – save your money for the good stuff!