California airport explodes in popularity as major airlines locked in ‘turf war’

San Diego is flying high — leaving some of the world’s biggest cities in the dust.

San Diego International Airport has been crowned the fastest-growing major airport on the planet in 2026, zipping past better-known heavyweights as an increasingly fierce airline turf war sends flights soaring.

The single-runway Southern California airport, better known as SAN, has seen the number of passenger flights jump a whopping 13% compared with 2025, according to a new analysis from Simple Flying.

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For an airfield that already moves tens of millions of passengers alongside Washington Dulles International Airport and Honolulu airport, double-digit growth is unusual. Getty Images/iStockphoto With that surge, San Diego outpaced Hanoi’s Noi Bai International Airport and Zurich Airport, which both saw a 12% jump.

For an airfield that already moves tens of millions of passengers, double-digit growth is unusual. So, what’s fueling the boom?

The aviation hotshot has two rival airlines largely to thank for its meteoric rise — Southwest Airlines and Alaska Airlines, both battling for dominance in the suddenly explosive market.

Runway 9 at San Diego International Airport is seen with the old and new Terminal 1. The San Diego Union-Tribune via Getty Images Southwest has been scrambling to lock down its crown as SAN’s king — adding 10 new destinations to turn the hub into its biggest California battleground.

Alaska Airlines, also keen on growing their presence at what’s become a key West Coast hub for the brand, is adding half a dozen new routes and boosting flight departures by nearly 40% year-over-year.

With the two behemoths eating up precious and limited asphalt space, other, carriers with limited clout are now reportedly being squeezed out.

Frontier Airlines recently chopped its San Diego schedule by 20%, for example — as real estate became limited and sent costs soaring.

So far, legacy heavyweights like Delta, American, and United have largely kept their schedules unchanged.

The rush of activity has been raising eyebrows in the industry, as the airport can’t actually expand beyond its current boundaries, due to its unique city center location.

The latest changes come on the heels of a record-breaking 2025, when San Diego International welcomed 25.32 million passengers — the busiest year in its history.

That was up 0.3% from 2024, with international passenger traffic surging 8%, according to airport officials.

The airport also rolled out a shiny new Terminal 1 last September, replacing its aging predecessor as part of a multibillion-dollar modernization effort, and bringing 19 pristine new gates to the airfield.

During the terminal’s first three months of operation, passenger traffic climbed more than 11% compared with the same period a year earlier.