The best time of year is September and October, when the ocean is warm enough for most swimmers to get in the water without a wetsuit, and the hordes of tourists have left. Winter months are considered "off-season," so you can get lower hotel rates and still enjoy great weather. No matter the time of year, dressing in layers is recommended, as the temperature can change in short distances due to microclimates. San Diego's weather is dry, so carrying water with you is essential! The neighborhoods of La Jolla, Ocean Beach, and Pacific Beach have only one main road leading in and out. Try to plan your visit around the morning and evening rush hours or you may get caught in a bottleneck with a long wait time.