What outfit should I wear when traveling to San Francisco in May?

The weather in San Francisco tends to vacillate between cool and warm temperatures. In order to dress appropriately and be comfortable all day, you should dress in layers. Start with a good pair of jeans, a t-shirt and a lightweight sweater. For your outerwear, choose a puffer jacket to add some insulation in case the wind picks up. Finally, San Francisco is best explored on foot, so wear a comfortable pair of sneakers.