Southwest Airlines announced plans to increase nonstop service from Charles M. Schulz–Sonoma County Airport (STS) in Santa Rosa, California, to Denver, Colorado, starting March 11, 2027. The carrier began weekly Saturday flights on April 7, 2026, and will raise frequency to five days a week (Thursday through Monday) by August 2026, with nearly daily flights during Thanksgiving and Christmas periods.
Southwest carried 20,077 passengers in June 2026 across routes including Burbank, San Diego, Las Vegas, and Denver from Sonoma County. The airline transported 53,899 passengers through the first half of 2026 at STS, operating flights with a 67% load factor
in June and 66% for the first six months. Southwest’s progressive expansion aims to mature the new service gradually.
Passenger Growth and Airline Performance at Sonoma County Airport
Charles M. Schulz–Sonoma County Airport recorded 92,759 passengers in June 2026, a 24.5% increase compared to June 2025 and 27.2% above pre-pandemic levels recorded in June 2019. Through the first half of 2026, passenger traffic reached 409,425, up 7.6% from the same period last year and 29% from 2019 figures.
Alaska Airlines remains the largest carrier at STS, serving 303,673 passengers in the first six months of 2026—a 21% rise over 2025. Delta Air Lines plans to begin twice-daily nonstop flights
from Sonoma County to Salt Lake City on October 6, 2026. Alaska Airlines will resume seasonal service to Palm Springs on September 10, 2026. American Airlines carried 13,748 passengers in June 2026, a 4.3% increase, but its January to June total declined 6.4% to 51,853 passengers, operating 89 departures in June with a shift toward smaller Embraer E175 regional jets.
Competition has intensified on nonstop routes to San Diego and Las Vegas, served by both Alaska and Southwest Airlines, with up to five daily flights to Southern California destinations from Sonoma County.
Official Statements on Service Growth and Competition
Southwest Airlines spokesperson Chris Perry said, “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.” Airport Manager Jon Stout confirmed Southwest’s plan for daily Denver flights as of March 11, 2027.
Stout noted, “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 also raised concerns about public disclosure policies related to noise performance, questioning, “How far do they want to take the shaming side of it?”
Noise Reduction Efforts and FAA Coordination
Sonoma County Airport is
addressing rising noise complaints with the proposed Fly Quiet noise-reduction program, which staff will present to the Sonoma County Aviation Commission on August 20, 2026. The commission’s recommendations will be considered by the Sonoma County Board of Supervisors later this year.
The Fly Quiet program is distinct from anticipated changes to departure procedures that have generated community concerns. Airport staff and consultants await the Federal Aviation Administration’s release of recommended procedural changes expected on FAA’s online portal by early August 2026.
Passenger traffic declined from January to March 2025 after Avelo Airlines ceased Sonoma County service in May 2025 and
before Southwest began flying. The traffic growth seen since April 2026 correlates with Southwest’s market entry and Alaska Airlines’ increased frequencies, contributing to the airport’s positive passenger trends in 2026.
