San Diego is right in the range that you are describing. Average highs in August are ~75. I'm biased though since I lived in San Diego for a couple of years and have never lived in or near San Francisco. Inland is much hotter in San Diego though.
A 100* heat wave in LA only clocks like 82* in san diego. Then again on that 100* LA day it is still only like 85* on the coast.
We're talking about the same SF from this summer where the heat waves were just as bad as SoCal? California climate change now means you're going to get heat waves pretty much everywhere.
Never felt remotely hot where I live in SF. Maybe towards Mission and further south/east.