Quick Verdict
Pick Key West if Mallory Square sunsets, Hemingway's six-toed cats, and Duval Street nightcaps trump Pacific surf access. Pick San Diego if La Jolla Cove, Balboa Park, and 300-day weather beat island eccentricity.
🤝 It's a tie — both rated 74 OVR
Key West
United States
San Diego
United States
Key West
San Diego
How do Key West and San Diego compare?
Both are sun-and-Pacific-or-Atlantic Americana, but one is a 2-square-mile end-of-the-road island and the other is a 4-million-population metro. Key West is Conch Republic eccentricity — Mallory Square's nightly sunset celebration with fire-jugglers and bagpipers, Hemingway's six-toed cats at the Whitehead Street house, $15 key lime pie slices at Kermit's, and Duval Street's Sloppy Joe's bar with Hemingway's old corner stool. San Diego is balanced California city — La Jolla's harbor seals and snorkel coves, Balboa Park's Spanish-Renaissance buildings, the USS Midway Museum on the harbor, and 70 miles of coastline that you can actually surf year-round.
Mid-range budgets sit at $350 Key West against $275 San Diego — Key West is one of America's most expensive small destinations because the only flights run on small planes ($400+ from MIA-EYW) and lodging is supply-constrained. San Diego wins on flight access (every major US airline runs SAN nonstop), nature variety, and value. Key West wins on walkability of a single dense Old Town and that genuinely-exotic-feeling-without-a-passport vibe.
Time Key West for January-March (peak season but spring-break-adjacent crowds spike March); time San Diego for April-June or September-November (the marine layer burns off by 11 AM). Don't combine them — they're 2,800 miles apart and a connection through Atlanta or Miami eats a day.
💰 Budget
🛡️ Safety
Key West
Key West is generally a safe small city for tourists. Old Town is well-policed and busy; the main risks are alcohol-related incidents (Duval Street late-night), aggressive scooter rentals on busy streets, sun exposure, and the seasonal hurricane risk. Petty theft from rental scooters and unattended beach belongings does occur. The island's relaxed, party-oriented culture means common sense is your best safety tool.
San Diego
San Diego is one of the safer large cities in the US for visitors. The main tourist areas — Gaslamp Quarter, Balboa Park, La Jolla, Coronado, and the beaches — are generally safe and well-policed. The East Village and parts of downtown near the trolley station have some street homelessness and petty crime, but serious violent crime targeting tourists is rare. Exercise normal urban precautions.
🌤️ Weather
Key West
Key West has a tropical savanna climate moderated by surrounding water — temperatures stay narrowly between 18°C (winter low) and 32°C (summer high) all year. There is a wet season (May–October, with afternoon thunderstorms and hurricane risk) and a dry season (November–April, which is also peak tourist season). Hurricane risk is real — Hurricane Irma in 2017 caused major damage to the Lower Keys.
San Diego
San Diego has the best year-round climate of any major city in the continental United States — a Mediterranean climate with warm, dry summers and mild, occasionally rainy winters. Average temperatures stay between 57°F and 77°F all year. The main quirk is "May Gray" and "June Gloom" — a marine layer of coastal fog that rolls in from the Pacific each morning, usually burning off by noon but sometimes persisting all day along the beach.
🚇 Getting Around
Key West
Key West Old Town is small (about 2 miles by 4 miles total island) and the historic centre is almost entirely walkable. Bicycles are the favourite local transport — flat terrain, dedicated bike lanes, and bike racks everywhere. The Duval Loop bus is free; Uber and Lyft operate but are more expensive than in Miami. Renting a car for the week is unnecessary unless you're visiting other Keys; parking in Old Town is scarce and expensive ($4-8/hour, $25/day in city lots).
Walkability: Old Town is one of the most walkable small-city centres in America — flat, compact, shaded by tropical canopy, and full of architectural detail. The full Duval Street walk takes 25 minutes end to end. Bicycles extend the comfortable range to the entire island.
San Diego
San Diego is primarily a car-dependent city, though downtown, the Gaslamp Quarter, and Balboa Park are very walkable. The San Diego Trolley connects downtown with Mission Valley, Old Town, and the Mexican border. Getting to La Jolla, the beaches, and Coronado is most convenient by car or ride-hail. The Coaster commuter rail connects downtown to North County beaches.
Walkability: Downtown San Diego and the Gaslamp Quarter are highly walkable. Balboa Park, Little Italy, and the Embarcadero are all connected by foot. However, San Diego is a sprawling metro — getting between neighborhoods like La Jolla, Mission Beach, and Old Town requires wheels or a ride.
📅 Best Time to Visit
Key West
Jan–Apr, Dec
Peak travel window
San Diego
Mar–Jun, Sep–Nov
Peak travel window
The Verdict
Choose Key West if...
you want a quirky, walkable, southernmost-US tropical destination with Hemingway history, the Conch Republic, the best key lime pie, and a daily sunset ritual
Choose San Diego if...
you want Southern California's laid-back beach city — La Jolla sea lions, Balboa Park + Zoo, Coronado, the Gaslamp Quarter, craft beer, and a Tijuana border hop
Key West
San Diego
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