Southwest And Alaska Add 17 New San Diego Routes
Southwest and Alaska Airlines have announced 17 new nonstop routes from San Diego International Airport, significantly boosting capacity and competition at
Southwest Airlines and Alaska Airlines have announced 17 new nonstop routes from San Diego International Airport (SAN). The carriers are adding a combined 4.4 million more seats to and from the airport in 2026, according to data from Cirium Diio.
Alaska Airlines has added six new routes. Southwest Airlines has introduced 11 new services. Many of these flights have already commenced operation.
Alaska Airlines Bets On Mexico And More
Alaska Airlines' new routes include a notable service to Loreto in Baja California, Mexico. US Department of Transportation data shows Aeromexico last served the route in 2006.
That carrier operated between 2002 and 2006 but only achieved a 61.1% seat load factor, primarily using McDonnell Douglas MD-87 aircraft. Alaska Airlines will operate the Loreto route with two weekly flights during the winter using its 76-seat Embraer E175 jets. The airline ended its San Francisco to Loreto service in April 2026.
Southwest Expands Its Hybrid Network
Southwest Airlines calls itself a hybrid operator, having moved far from its low-cost carrier roots. Seven of its 11 new routes from San Diego have been served by the airline before. All 11 of the new links face head-to-head competition with at least one other carrier.
Alaska Airlines competes on all of them. A schedule analysis shows the two airlines now compete directly on 29 routes from San Diego. "The competition is truly heating up," the source report states.
Market Share And Capacity Surge
The expansion has dramatically shifted market shares at San Diego International Airport. Southwest Airlines now holds a record 37% share of the airport's total capacity, up from 35% in 2025. Alaska Airlines' share has jumped from 19% to 24% over the same period.
The carriers' capacity figures for 2026 show substantial growth.
| Carrier | 2026 Round-Trip Seats | Year-Over-Year Change |
|---|---|---|
| Alaska Airlines | 8.4 million | Up 35% from 2025 high |
| Southwest Airlines | 13.3 million | Up 20% year-over-year |
Southwest now serves 47 routes from San Diego. The largest share of its capacity, 33%, is dedicated to flights within California. It serves seven California airports: Fresno, Oakland, Sacramento, San Francisco, San José, Santa Barbara, and Santa Rosa.
Despite adding new service to Santa Barbara and Santa Rosa, Southwest's 2026 intra-California capacity from San Diego is only at the seventh-highest level in two decades. This is due to significant declines in available seats to Oakland, San Francisco, Sacramento, and San José.
The source report questions whether such rapid growth can be sustained. That is not yet clear which carrier might adjust its strategy first in the increasingly competitive San Diego market.
