I wish there were a more technical, perhaps more modern analysis of San Francisco’s microclimates, but this is all I could find in visual form. The temperature descriptions are relative to the area’s overall climactic patterns — in my estimation, “moderate” means probably above 72F for the high in summer, “cool” means below 68F. “Hot” is probably in the 74-76F range.
To experience the sunniest and warmest summers in San Francisco, the obvious neighborhoods to live in are the Excelsior District, Visitacion Valley, Crocker-Amazon, The Bayview and Hunters Point. Nice compromises would be Portrero Hill, The Mission, and anything along the eastern waterfront. According to this map, the only difference between zone 6 and 7 is wind, not temperature, but having checked some local weather stations, it seems that the southeast quadrant is in fact a degree or two warmer on average.
