Southwest Airlines initiated weekly nonstop service between Charles M. Schulz–Sonoma County Airport (STS) in Santa Rosa, California, and Denver, Colorado, on April 7, 2026. The airline announced on July 25, 2026, plans to increase this Denver route to daily flights starting March 11, 2027. Before reaching daily frequency, Southwest will expand flights to five days a week (Thursday through Monday) beginning in August and September 2026, with near-daily service during Thanksgiving and Christmas holiday periods.
Passenger Traffic Growth at Sonoma County Airport
Passenger traffic at Charles M. Schulz–Sonoma County Airport rose sharply in June 2026, accommodating 92,759 travelers—a 24.5% increase from June 2025 and 27.2% increase compared
to June 2019. Through the first half of 2026, total passenger volume reached 409,425, up 7.6% over the same period in 2025 and 29% higher than 2019 levels. Airport Manager Jon Stout projected 2026 year-end traffic between 950,000 and 1 million passengers.
Southwest Airlines transported 20,077 passengers in June 2026 between Sonoma County and destinations including Burbank, San Diego, Las Vegas, and Denver. Year-to-date through June, Southwest carried 53,899 passengers from Sonoma County with an average load factor of 66%. Alaska Airlines remained the largest carrier at the airport during the first half of 2026, moving 303,673 passengers—a 21% increase
from 2025. Alaska carried 58,934 passengers in June with a load factor declining to 79% from 83% a year earlier.
American Airlines reported 13,748 passengers in June 2026, a 4.3% rise from June 2025, despite a 6.4% drop in first-half 2026 passenger totals. The airline maintained 89 departures in June, equivalent to the previous year, but shifted primarily to smaller 76-seat Embraer E175 jets from 120-seat Airbus A319 aircraft, contributing to a load factor increase to 86% from 70%.
Airline Competition and Route Strategies
Competition on Sonoma County nonstop routes to Southern California cities is intensifying. Both Alaska Airlines and Southwest Airlines offer service to
San Diego, combining for as many as five daily flights. This competitive environment has led airport officials to enhance monthly monitoring of carrier performance to maintain strong service quality. Jon 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.” Southwest spokesperson Chris Perry remarked, “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.”
Delta Air Lines is set to begin twice-daily
nonstop flights from Sonoma County to Salt Lake City starting October 6, 2026. Alaska Airlines will resume seasonal flights to Palm Springs on September 10, 2026. Avelo Airlines ended all service at Sonoma County in May 2025.
Noise Management Initiatives and Operational Changes
Amid increasing passenger volumes and flight operations, Charles M. Schulz–Sonoma County Airport is developing a noise reduction program called Fly Quiet. The program seeks to address rising community noise complaints and includes components being reviewed by the Sonoma County Aviation Commission as of August 20, 2026. Discussion of program cost, noise modeling, and public identification of poorly rated airlines remains ongoing. Airport Manager
Jon Stout commented on the potential approach to publicly rating airlines, stating, “How far do they want to take the shaming side of it?”.
The noise reduction proposal is distinct from possible Federal Aviation Administration–related changes to departure procedures. The airport and its consultants are awaiting the FAA’s review and uploads of recommended procedure changes to the FAA online portal as of early July 2026.
Passenger numbers declined from January through March 2025 following Avelo Airlines’ service termination and before Southwest Airlines launched flights in April 2026. Since then, passenger traffic has accelerated, driven in part by added frequencies from
Alaska Airlines and new Southwest service.
