San Francisco's most famous resident has a name, a Twitter, and a physics degree. Why the Bay has 10 climates in 7 miles — and why Mark Twain never said that quote*.
Outer avenues live in Karl July–Aug. Hoodie year-round. Ocean keeps it 55–65°F.
Bernal Hill blocks fog. Warmest hood — 10°F hotter than Sunset, same hour.
Market St funnels ocean air. Layers fly; lunch al fresco = gamble.
Cross a bridge: 90°F in Walnut Creek while SF shivers at 58°F.