Southwest Airlines began weekly nonstop service between Charles M. Schulz–Sonoma County Airport (STS) in Santa Rosa, California, and Denver, Colorado, on April 7, 2026. The carrier has notified airport officials it plans to increase the route frequency to daily flights by March 11, 2027. The expansion will be phased, starting with five weekly flights from Thursday through Monday beginning in August 2026, followed by additional increases in September, near-daily service during the Thanksgiving and Christmas holiday periods of late 2026, and intermittent flights on other days.
Passenger Traffic Growth at Sonoma County Airport
Passenger throughput at Sonoma County Airport has risen sharply in 2026. The airport recorded
92,759 passengers in June 2026, representing a 24.5% increase compared to June 2025 and a 27.2% rise over June 2019, the last full pre-pandemic year. The first half of 2026 saw 409,425 passengers pass through STS, a 7.6% increase from the same period in 2025 and 29% above 2019 figures. Southwest Airlines carried 53,899 passengers through June 2026, with load factors of 67% in June and 66% for the first six months. Alaska Airlines remains the largest carrier at the airport, increasing passenger numbers by 21% to 303,673 in the first half of 2026.
Airport Growth Projections and Other Airlines’ Service Updates
Airport Manager Jon Stout indicated STS
is on track to handle between 950,000 and 1 million passengers in 2026. Delta Air Lines plans to add twice-daily nonstop service to Salt Lake City starting October 6, 2026. Alaska Airlines will resume seasonal flights to Palm Springs on September 10, 2026, an earlier start than the previous year. American Airlines transported 13,748 passengers in June 2026, up 4.3% year-over-year, but its first half 2026 total declined 6.4% to 51,853 passengers. American maintained the same number of departures in June 2026 as in June 2025 (89 flights), but shifted from 120-seat Airbus A319 aircraft to 76-seat Embraer E175 regional
jets.
Competition on Regional Nonstop Routes
Southwest Airlines and Alaska Airlines compete on nonstop routes from Sonoma County to San Diego and Las Vegas, with up to five daily flights each to San Diego. In June 2026, Alaska carried 58,934 passengers on flights from STS, an increase of 17% compared to the prior year, though its load factor declined to 79% from 83%. Avelo Airlines ceased service to Sonoma County in May 2025 after carrying 10,950 passengers in June 2025 and 73,380 for the first half of that year. Airport management said it is monitoring competitive route performance on a monthly basis to ensure the
strength of all carriers operating at STS.
Noise Management and Fly Quiet Program
Charles M. Schulz–Sonoma County Airport is addressing increasing noise complaints with the proposed Fly Quiet noise-reduction program. Details of seven program components are scheduled for presentation to the Sonoma County Aviation Commission on August 20, followed by a presentation to the Board of Supervisors later in the year. The program includes public reporting features such as airline noise-performance report cards, though airport officials are considering how aggressively to publicize airline ratings. Airport Manager Jon Stout expressed concern about overemphasis on negative ratings, asking, “How far do they want to take the shaming side
of it?” The Fly Quiet program is distinct from potential changes to departure procedures, which remain pending FAA discussion.
Southwest Airlines spokesperson Chris Perry stated, “We intentionally started small with our new service at (Sonoma County airport) (as we do with all new destinations), and we’re now maturing that service.” Stout said increased competition among carriers prompts close monthly review of route performance to ensure each airline’s viability at the airport.
