dailynewsnblog
Alaska Airlines and Southwest Airlines have been growing exceptionally strongly at 
San Diego International Airport (SAN), partly due to the retaliatory nature of the two operators. The pair have announced 17 new routes for 2026/2027, many of which have already started.
Both carriers have record capacity at SAN. In 2026, Cirium Diio data indicates that Alaska Airlines has 8.4 million round-trip seats for sale, up by a staggering 35% compared to the previous high in 2025. Southwest has a record 13.3 million seats, up 20% year-over-year. The pair have added 4.4 million more seats to/from SAN in 2026. Will such growth in so little time be sustainable? Time will tell.
Alaska Airlines Has Added Six SAN Routes
It is always good when brand-new routes (those that have not had nonstop flights before) are launched or when markets return after a long absence. That’s the case with Loreto, which is in Baja California and is growing in popularity as a tourist destination.
US Department of Transportation (DOT) data shows that flights to the Mexican destination were last available with 
Aeromexico in 2006. The carrier operated between 2002 and 2026 but only filled 61.1% of seats. The McDonnell Douglas MD-87 was primarily deployed.
Clearly, 
Alaska Airlines will be betting on a substantially better result. Only having two flights a week during the winter on the 76-seat Embraer E175 (shown above) will help. So, too, will the ability to connect to other flights at SAN, including to 
San Francisco International Airport (SFO). The airline’s SFO-Loreto service ended in April 2026.
Start Or Relaunch Date | SAN To… | Alaska Airlines’ Operations* | Served By The Airline Before? | Airport Pair Served By Another Carrier? |
|---|---|---|---|---|
March 18, 2026 | Tulsa, OK | Daily Horizon Air E175 | No | No. Last flown by Frontier in 2018. Before that, by Expressjet in 2007/2008 |
April 21, 2026 | Santa Barbara, CA | Two daily Horizon Air and SkyWest E175 | Yes: 2021/2022 | Southwest (see later in this article). Others have served the market before, such as Expressjet in 2007/2008 and WestAir Commuter Airlines until 1990 |
April 22, 2026 | Dallas/Fort Worth, TX | Two daily 737-800, 737-900ER, 737 MAX 9 | No | American and Frontier |
April 22, 2026 | Oakland, CA | Four daily Horizon Air and SkyWest E175 | No | Southwest. The now-defunct Spirit pulled out in 2025. But with four daily services, Alaska Airlines’ offering will be significantly more competitive than Spirit’s, especially for higher-yielding travelers. It’ll be much more damaging to Southwest |
April 22, 2026 | Raleigh/Durham, NC | Daily, mainly on the 737 MAX 9 and 737-900ER | No | Breeze. It’s the first time that two airlines coexist |
December 19, 2026 | Loreto, MX | Two weekly Horizon Air E175 | No | No. See earlier comments |
* Known as of September 23 |
Southwest Has These 11 New SAN Routes
Southwest calls itself a hybrid operator nowadays. Given its widespread changes, it has, in many ways, moved far from its low-cost carrier roots. In 2025, SAN was the operator’s 12th most-served airport for total seats for sale. With the big growth year-on-year, it is now tenth.
Seven of the 11 routes have been served by 
Southwest before. All 11 links have head-to-head competition with at least one other carrier, with Alaska Airlines on all of them. Schedule analysis from the start of 2026 through next spring shows that the pair now face each other on a considerable 29 routes from SAN. The competition is truly heating up. Which carrier will blink first?
Start Or Relaunch Date | SAN To… | Southwest’s Operations* | Served By The Airline Before? | Airport Pair Served By Another Carrier? |
|---|---|---|---|---|
March 5, 2026 | Kahului, HA | Daily 737 MAX 8 | Yes: 2021-2022 | Alaska Airlines |
March 5, 2026 | Puerto Vallarta, MX | Up to five weekly 737-700 | Yes: 2018-2020 | Alaska Airlines |
March 5, 2026 | Seattle, WA | Daily, mainly 737-700 and 737 MAX 8 | Yes: 2014-2020 | Alaska Airlines, Delta |
March 7, 2026 | Bozeman, MT | Up to five weekly 737-700, 737-800, 737 MAX 8 | Yes: 2021-2022 | Alaska Airlines |
March 7, 2026 | Spokane, WA | Up to five weekly 737-700, 737-800, 737 MAX 8 | Yes: 2017-2020 | Alaska Airlines |
April 7, 2026 | Santa Rosa, CA | Up to two daily 737-700 | No | Alaska Airlines |
June 4, 2026 | Boston, MA | Daily, mainly 737 MAX 8 | No | Alaska Airlines, Delta, JetBlue |
August 4, 2026 | Santa Barbara, CA | Daily, mainly 737-700 and 737-800 | No | Alaska Airlines |
November 21, 2026 | Fort Lauderdale, FL | Five weekly 737 MAX 8 | No | Alaska Airlines and JetBlue |
March 13, 2027 | Kona, HA | Two weekly 737 MAX 8 | Yes: 2021/2022 | Alaska Airlines |
March 13, 2027 | Lihue, HA | Two weekly 737 MAX 8 | Yes: in 2021/2022 | Alaska Airlines |
* Known as of September 23 |
Southwest Now Has 37% Of SAN’s Seats
Southwest has a record 13.3 million seats to/from SAN in 2026. This means that the carrier now has a 37% share of the airport’s total capacity, which is, not surprisingly, the highest proportion to date. It has risen from 35% last year. Alaska Airlines’ market share has jumped from 19% in 2025 to 24% this year.
Southwest now has a total of 47 routes from SAN. By far the largest share of capacity is within California (33%). Seven airports are now served: Fresno, Oakland, Sacramento, San Francisco, San José, Santa Barbara, and Santa Rosa. However, despite new service to Santa Barbara and Santa Rosa, 2026 capacity is not at a record high. It is only at the seventh-highest level in the past two decades, due to big declines in available seats to Oakland, San Francisco, Sacramento, and San José.
