When I lived in the bay area most places didn’t have A/C. It only got hot a few days though, and I was close to the water. And it always cooled off at night.
When we moved to San Jose none of the houses had air conditioning. It did cool down quite well at night. When we bought our last house we converted the garage to a game/family room we put a window air in there and that was where we stayed when it got to hot. We left the garage doors on so it could be converted back to a garage if the buyers wanted to.