Sonoma County airport saw passenger traffic surge 47.1% last month from a year earlier, fueled by Southwest Airlines’ arrival in Santa Rosa and continued expansion of airline service from other carriers.
Charles M. Schulz–Sonoma County Airporthandled 95,221 passengers in September, up from 64,711 a year earlier, according to statistics released Friday. That made it the busiest September on record, although traffic slipped slightly from August’s all-time monthly peak of 96,205 passengers.
Through the first nine months of 2026, the county-owned airport served 696,583 passengers, up 17.2% from 594,287 during the same period last year.
Airline operations, counting arrivals and departures separately, rose 42% to 1,372 from 966 in September 2025. Through September, operations increased 20.8% to 10,278.
Southwest fuels growth
Southwest, which launched Santa Rosa–Denver flights in April, accounted for 26,213 September passengers, compared with 26,655 in August.
The carrier filled 76% of its available seats in September, a measure known as load factor, up from 73% in August and 68% in July.
Alaska Airlines remained the airport’s largest carrier, handling 58,563 September passengers, up 6.4% from a year earlier. However, its load factor dropped to 67% from 78% in September 2025, as flight operations increased 19.4%.
Airport Manager Jon Stout said Monday that Alaska’s expanded flight schedule outpaced passenger growth.
“They added that additional frequency, and the (passenger) volume is a little slow to adjust,” Stout said.
He expects Alaska’s load factor to improve over time, similar to Southwest’s experience since launching service.
American Airlines handled 10,445 September passengers, an 8% increase from a year earlier, while its load factor climbed to 83% from 73%.
Although Southwest and American recorded fewer flight operations in September than August, Stout said that largely reflected September having one fewer day, rather than significant service reductions.
More flights, connections ahead
The September results preceded Delta Air Lines’ Oct. 6 launch of twice-daily nonstop Salt Lake City flights, restoring the airport to four commercial carriers.
Alaska remains scheduled to introduce nonstop flights to Boise, Idaho, and Phoenix on Nov. 1, while ending service to Ontario in Southern California on Oct. 31, Stout said.
Southwest’s plans for daily Denver servicestarting March 11, 2027, also remain intact. Stout said the airline’s updated schedule maintains that frequency through at least early June of next year.
Meanwhile, the airport and The Landline Company announced Monday that a secure motorcoach connection to San Francisco International Airport will begin Nov. 17, offering eight nonstop round trips daily.
Participating airline passengers departing SFO will be able to check bags and clear security in Santa Rosa before boarding coaches that deliver them directly to SFO’s secure terminal area.
Airport expansion and business activity
The passenger growth comes as the airport plans a 15-year expansion and modernization program addressing parking shortages, crowded ticket counters and security checkpoints.
The airport also is expanding its aircraft parking apron from four to six positions, with covered walkways planned between the terminal and airliners to shield passengers from rain and sun. The canopy system also is planned to accommodate Landline motorcoach passengers.
Stout said Monday that the next apron construction contract amendment is targeted for Sonoma County Board of Supervisors consideration in December, although no meeting date has been set.
Increased flight activity also is benefiting airport concessions and rental car businesses, Stout said. The periods between flights when the terminal is relatively quiet are becoming shorter.
“But it is definitely spreading out throughout the day and getting to be almost all-day activity,” Stout said.
Concessionaires’ business has been growing roughly in parallel with passenger counts, he said, while rental car operators are experiencing capacity pressures as demand increases.
“They’re bursting at the seams too,” Stout said.
Plans to handle the growth
The airport is seeking a design-build team for a consolidated rental car facility, with construction potentially starting in summer or fall 2027, the Journal reported Aug. 21. The project is part of the airport’s broader modernization plans, which require individual approvals and funding commitments from the Board of Supervisors.
