Southwest has come to dominate Southern California, but Cirium schedule and DOT data reveal sharp divergence in how its six airports across the region are performing — from a striking revenue turnaround at Long Beach to persistent underperformance at LAX and Ontario.

The departure picture first. Until 2022, Southwest's operations at LAX and San Diego were similarly sized. They then diverged. San Diego completed its post-pandemic recovery rapidly, while LAX never came close. Southwest briefly rebuilt LAX flying, then retrenched in 2024.

At San Diego, Southwest has had to fend off Alaska. At LAX, it could have decided to fight everyone, and chose not to.

The secondary airports in the LA Basin recovered fairly quickly after the pandemic. Long Beach grew rapidly for Southwest after JetBlue walked away during the crisis. Departure counts have since sagged at all the region's airports versus their peaks, except Orange County, where Southwest has flown as much as the airport allows.

Part of the decline reflects rising gauge offsetting fewer flights — but only at four of the six airports. Southwest's systemwide seats per departure have climbed as the carrier retires 737-700s and adds MAX 8s. Burbank and Orange County have largely missed that shift, and for different reasons.

Burbank is a facility problem. The existing terminal is compact, with little room to flow larger aircraft through, so Southwest has kept its -700s in the market. A new terminal opens in October, and changes in aircraft assignment are expected to follow.

Orange County is a regulatory artifact. The airport's noise ordinance functions in practice as an annual passenger cap, which incentivizes Southwest to fly smaller — and louder — -700s so it can operate more flights without breaching the cap.

Load factors tell the next part of the story. Comparing each airport against Southwest's systemwide average, Long Beach stands out. Its loads trailed the system for years, but once Southwest found the right mix and trimmed flights, load factor soared. It has beaten the system average nearly every month since November 2025.

Burbank shows good upward movement but sits below average despite operating almost exclusively the smaller -700s. Southwest runs a more business-friendly schedule there and earns high yields, which produces lower loads, especially on short hops. Orange County follows the same pattern, with better loads because the passenger cap keeps capacity in check.

San Diego has maintained above-system loads even through the heavy capacity additions of its fight with Alaska. The clear weak spot is Ontario, consistently below system average with none of the gains seen elsewhere.

Load factor, however, is only part of the picture. Stage length-adjusted unit revenue — how much those flights actually generate — shows the same Long Beach pattern in sharper relief. Long Beach was the Southern California laggard for its entire existence on this measure, improving slowly until the first quarter of this year, when it beat the system average for the first time. It now sits above both LAX and San Diego on an aggregate basis and is closing on Ontario.

Orange County and Burbank confirm that smaller planes, lower loads and high fares still work financially for Southwest. The open question is whether that holds when larger aircraft begin moving into Burbank in November, after the new terminal opens.

Ontario remains above system average on unit revenue but has fallen off lately — not because revenue is declining, but because it is not growing as fast as at the markets now excelling.

Then the two big airports. LAX is smaller than it was and continues to underperform the system on revenue — and that captures only one side of the equation. LAX is by far the most expensive airport in the set to operate from, a real concern for Southwest with no easy answer.

San Diego has been a struggle on current numbers, but it reflects a deliberate strategic investment to hold off Alaska, intensified over the last two quarters as the new terminal opened and capacity expanded. It is a long-term project; short-run profitability is suffering, and the expectation is that things will settle down. With Burbank's new terminal and Long Beach's revenue inflection, the composition of Southwest's Southern California franchise looks set to keep shifting.