🇺🇸 Phoenix vs 🇺🇸 San Francisco

Phoenix is the hottest major city in the United States, with summer temperatures regularly exceeding 110°F and over 100 days above 100°F annually. The city's Valley of the Sun location in the Sonoran Desert and massive urban heat island make nights especially extreme — often staying above 90°F. Monsoon season from July through September brings dramatic thunderstorms and haboobs.

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.