Fisherman's Wharf in December

September and October offer the best weather — warm, clear days with minimal fog. Hotel prices drop after Labor Day but before Halloween crowds arrive. April through June brings mild temperatures but afternoon fog that can roll in fast. Summer means peak tourist season and peak fog. July temperatures rarely hit 70 degrees, and the marine layer can blanket the wharf until 3pm. But that's when the sea lions are most active, and ferry rides to Alcatraz book solid. Winter brings rain and smaller crowds. December through February sees frequent storms, but clear days offer spectacular views of snow-capped mountains across the bay. Hotel rates drop to their lowest, sometimes 40% off peak season. Weekdays beat weekends year-round. Tuesday through Thursday you can actually move through Pier 39 without playing human pinball.