Southwest Launches 11 New Routes From This Major US Airport [Full List]

Published Aug 25, 2026, 2:00 PM EDT Luke has over a decade of experience as a travel writer and aviation analyst. As a passionate traveler based across the Middle East and Asia, Luke offers strong insights into the industry. Based in South East Asia. San Diego International Airport (SAN) is emerging as one of the biggest growth markets in the Southwest Airlines network in 2026, with the carrier adding or restoring 11 nonstop routes compared with its Q3 2025 schedule. The expansion comes as Southwest continues to bolster its presence at San Diego following the opening of the airport's new Terminal 1 in September 2025. According to data from aviation analytics company Cirium for Q3 2026, Southwest will operate more than 2,000 flights across the 11 routes during the three months. These 11 routes represent more additions than at any other airport in its network during the same period. The routes are a mix of new services alongside airport pairings that have returned to Southwest's schedule. Southwest's 11 San Diego Route Additions In 2026 Credit: Shutterstock Southwest's expansion covers destinations across the US while also strengthening its intrastate California network. Together, the routes account for 2,068 scheduled flights during Q3 2026. Several are notable as they give Southwest entry into markets that were either completely absent from its San Diego schedule in Q3 2025 or had been dropped previously. Rank Destination Q3 2026 Flights Launch / Return Service 1 Fresno (FAT) 342 October 2, 2025 Twice daily 2 Seattle (SEA) 300 March 5, 2026 Daily, year-round 3 Santa Rosa (STS) 286 April 7, 2026 Daily 4 Boston (BOS) 184 June 4, 2026 Daily, year-round 5 Maui (OGG) 184 March 5, 2026 Daily, year-round 6 Eugene (EUG) 184 March 5, 2026 Daily, year-round 7 Spokane (GEG) 130 March 7, 2026 Saturday-only, seasonal 8 Omaha (OMA) 126 November 22, 2025 Seasonal 9 Santa Barbara (SBA) 116 August 4, 2026 Daily 10 Bozeman (BZN) 114 March 7, 2026 Saturday-only, seasonal 11 Colorado Springs (COS) 102 October 2, 2025 4x weekly Three of these routes serve destinations in California: Fresno, Santa Rosa and Santa Barbara. At the other end of the spectrum, Boston represents one of the longest new domestic connections from San Diego, while Maui extends Southwest's reach into Hawaii. Fresno is the busiest of the 11 additions, with 342 scheduled flights as part of a twice-daily service, followed by Seattle with 300 and a connection with Santa Rosa seeing 286 flights. San Diego Ahead Of The Pack For New Additions Credit: Shutterstock Southwest's expansion in San Diego is notable for adding almost double the number of routes compared to the next-highest airport in its network. Knoxville's McGhee Tyson Airport (TYS) ranks second, with seven routes added over the same period. The route additions in San Diego arrived in three distinct waves, beginning with the spring 2026 launch of Eugene, Maui, Seattle, Bozeman and Spokane, followed by Santa Rosa and Boston in mid-2026 and finally Santa Barbara in August. Loading map… Drag to explore The growth comes at a time when Southwest is already comfortably the largest carrier at SAN. The airline holds over 34% of the market, ahead of second-placed Alaska Airlines at around 21%. The three major US legacy carriers ( American Airlines, Delta Air Lines and United Airlines) also maintain a sizable presence at SAN with between 11% and 12% of the market. During its Summer 2026 schedule, Southwest says it will reach an all-time high of 43 destinations from San Diego. This will involve up to 134 peak departures, rising to 139 departures on peak days in August and September. New Terminal 1 Opens Door To Growth Credit: Shutterstock Southwest's ability to add so many routes from San Diego is closely tied to the opening of the airport's new Terminal 1. The first phase opened in September 2025, replacing the 58-year-old original Terminal 1 and providing 19 new gates. The additional space has enabled Southwest to boost both the number of destinations it serves and the frequency of existing routes. SAN will continue to expand as Terminal 1's Phase 1B goes online, which is set to add another 11 gates and take its total to 30 gates once completed in 2028. San Diego is one of California's largest airports, ranking as the state's third-busiest by passenger count after handling a record 25.32 million passengers in 2025.