Southwest Airlines launched weekly nonstop flights between Charles M. Schulz–Sonoma County Airport (STS) in Santa Rosa, California, and Denver International Airport on April 7, 2026. The airline notified airport officials it will expand this service from once-weekly Saturday flights to nearly daily starting March 11, 2027.
The frequency increase will be phased in over several months. Beginning August 2026, Southwest plans five flights per week from Thursday through Monday. Around the Thanksgiving and Christmas holiday periods in late 2026, the airline aims to operate flights almost daily. Between these peak periods, the schedule will vary from one to a few
flights weekly. Southwest spokeswoman 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.”
Passenger Traffic Growth at Sonoma County Airport
Charles M. Schulz–Sonoma County Airport reported handling 92,759 passengers in June 2026, a 24.5% increase over June 2025 and 27.2% above June 2019 figures. Through June 2026, total passenger volume reached 409,425, up 7.6% compared to the same period in 2025 and 29% above 2019 levels. Airport Manager Jon Stout said the facility is on track to handle between 950,000 and 1 million passengers by the end of
2026.
Alaska Airlines, the airport’s largest carrier, grew its passenger count by 21% in the first half of 2026 to 303,673 at Sonoma County. Meanwhile, Delta Air Lines announced plans to begin twice-daily nonstop flights to Salt Lake City starting October 6, 2026. Alaska Airlines will resume seasonal service to Palm Springs on September 10, 2026, a month earlier than in 2025. Avelo Airlines discontinued service at Sonoma County Airport in May 2025.
Southwest Airlines Passenger Volume and Competition
Since launching service in April 2026, Southwest Airlines carried a total of 53,899 passengers through June 2026 on routes including Santa Rosa to Denver, Burbank, San Diego,
and Las Vegas. Its aircraft operated with an average load factor of 67% in June and 66% for the first half of the year. Southwest’s expansion has compensated for the gap left by Avelo’s exit, which accounted for 10,950 passengers in June 2025 and 73,380 during the first half of that year.
American Airlines reported carrying 13,748 passengers in June 2026, a 4.3% increase from June 2025, although its cumulative first-half total fell 6.4% to 51,853. The airline maintained 89 departures in June 2026, consistent with the prior year, but replaced some 120-seat Airbus A319 jets with more 76-seat Embraer
E175 regional jets to increase load factors, which rose to 86% from 70% year-over-year. Competition has intensified on nonstop routes such as San Diego and Las Vegas, both served by Alaska and Southwest Airlines. For example, combined schedules could feature up to five daily flights to San Diego.
Fly Quiet Noise Reduction Program and FAA Procedure Updates
To address rising noise complaints, the Sonoma County Aviation Commission will review seven components of a proposed Fly Quiet noise reduction program on August 20, 2026. The commission’s recommendations will be presented later this year to the Sonoma County Board of Supervisors. Airport Manager Jon Stout noted ongoing discussions on how strictly
to enforce public noise performance ratings for airlines, asking, “How far do they want to take the shaming side of it?”
The Fly Quiet initiative is separate from potential changes to departure procedures that have raised community concerns. The airport and its consultants are awaiting Federal Aviation Administration engagement following submission of recommended procedure changes to the FAA’s portal by the week of July 20, 2026.
Official Statements on Growth and Competition
Southwest’s spokeswoman Chris Perry confirmed the carrier’s approach of initially small service launches, now evolving with route maturity. Jon Stout said Southwest advised the airport about its expanded Denver schedules starting March 11, 2027.
Stout emphasized monitoring airline performance monthly, stating, “Now that we actually have more competition, we’ll be looking at that on a monthly basis as well, because we want to make sure all of our carriers are strong.” He further pointed to the Fly Quiet program and its community noise considerations as integral to Sonoma County Airport’s growth management strategy.
