Southwest’s Network Expansion Continues With New Californian Market

Southwest Airlines is continuing its network expansion with Santa Rosa, California, to be added to the carrier’s route map next year.

Southwest has gone more than four years without entering a new market, but has now announced four new network points since July. Flights from Charles M. Schulz Sonoma County Airport (STS) will start on April 7, 2026, with service to four cities. Flights to Las Vegas Reid International (LAS) and San Diego International (SAN) airports will be operated daily, with SAN served 2X-daily on peak days.

Alaska Airlines and JetBlue Airways both serve the STS-SAN route on a seasonal basis, according to OAG Schedules Analyzer data. JetBlue and Spirit Airlines operate on the STS-LAS route.

Southwest service from STS to Hollywood Burbank Airport (BUR) will be flown 5X-weekly, while flights to Denver International Airport (DEN) will be operated 1X-weekly on Saturdays. Spirit and United already operate the STS-DEN route.

STS follows three previous network addition announcements by Southwest.

In April 2026, Southwest will add its first international market since 2021 with flights from Baltimore/Washington Thurgood Marshall International (BWI) and Orlando International (MCO) airports to St. Maarten. In February 2026, the all-Boeing 737 operator will start serving St. Thomas in the U.S. Virgin Islands—its first new market of any kind since 2021—from BWI and MCO. In March 2026, the carrier will enter the Knoxville, Tennessee market with 2X-daily service to Nashville, Tennessee and daily service to BWI, Dallas Love Field and MCO.

Service to the new airports in 2026 will correspond with Southwest initiating a number of changes to its business model, including adding bags fees and premium seating.

STS will be the 14th airport in California served by Southwest. The airline said it intends to “soon” announce another new addition to its network.

“We aren't slowing down in our pursuit to provide customers with more options,” Southwest COO Andrew Watterson says. “Adding [STS] to our route map provides more access to California's famed wine country for our customers and further solidifies our years-long commitment to California.”