Casual Chic Chick 3 I'd hear tourist in California in July say, "Yeah, we're going to go camping at Bodega Bay." "Bring some heavy coats, firewood and something to keep dry. You're going to feel like you're freezing to death," I'd respond. They'd look at me like I was crazy. They learned the hard way. Best season in the San Francisco Bay Area - October. If you're wondering why it can get so cold in San Francisco in the summer is this... The Sacramento and San Juaquin Valleys can get VERY hot (100+) in the summer. This heat rises, pulling air from the Sacramento & San Juaquin River Valleys. That air comes off the Pacific Ocean. (In Sacramento, we called it the Delta Breeze. It was more like a gale force wind.) As the air is pulled off the Pacific, it comes down from Alaska bringing with it foggy, cold, damp air. The result is a damp, cold coastline. I could almost judge what days were going to be real miserable at the beach based on the temperatures a day or two before in the valley.