🇺🇸 Philadelphia vs 🇺🇸 San Francisco

Philadelphia in the Delaware River valley has a humid subtropical climate transitioning to continental. The city's urban heat island is intense — dense rowhouse neighborhoods without significant green space are among the East Coast's most heat-vulnerable. The Delaware and Schuylkill Rivers provide some humidity while the Piedmont hills to the north create varied terrain.

San Francisco's climate is shaped by its position on a peninsula surrounded by the Pacific Ocean and San Francisco Bay. The coastal fog (Karl the Fog) rolls in through the Golden Gate each summer afternoon, keeping temperatures mild year-round. The city has dramatically different microclimates — the Sunset District fog-bound while the Mission basks in sun on the same day.