If you flew Southwest Airlines last year, your flight was less likely to be canceled than if you had chosen any other carrier, according to a prestigious industry report released Thursday. The annual Cirium On-Time Performance Review is viewed in the industry as the arbiter of operational excellence.
To be clear, Southwest did not win the whole enchilada. Delta Air Lines clocked the best overall on-time performance in North America, with 83.46% of its flights in 2024 getting to the arrival gate within 15 minutes of the scheduled arrival time. United Airlines and Alaska Airlines followed with 80.93% and 79.25% on-time arrival rates, respectively.
Southwest finished fifth overall on the continent, with a performance rate of 77.77%—almost two percentage points better than the previous year and more than one point better than the industry average of 76.37%.
Yet when it came to one key metric—the percentage of flights completed—Southwest Airlines bested all of its peers in 2024. The Dallas-based carrier achieved a remarkably low cancellation rate of 0.62%—more than a full percentage better than the industry average of 1.67%.
“Generally, a cancellation rate around 1% is considered strong, reflecting good operational reliability,” says Mike Malik, Cirium’s chief marketing officer. “Conversely, rates exceeding 2% may indicate potential operational challenges.”
In the inverse, in 2024, Southwest scored a 99.38% “completion factor,” the term Cirium uses for the percentage of scheduled flights that were not canceled. Over the entire year, Southwest flew 1,452,197 flights and canceled only 9,041.
In a statement provided to Forbes on Friday, Southwest chalked up its achievement to its “intentional investments to enhance the strength of our network operations control procedures, crew scheduling capabilities, and our ability to quickly adapt and recover from winter storms and other disruptions,” adding, “We worked hard to achieve the No. 1 ranking in completed flights. None of this would be possible without the dedication and focus of our employees, who perform at a high level every day.”
Ultra-low-cost carrier Spirit Airlines notched an impressive 0.68% cancellation rate last year, though it must be noted that it flew far fewer flights than the legacy carriers.
Among the other “Big Four” airlines in the U.S., Delta Air Lines had the second-best cancellation rate, of 1.05% (17,959 flights out of 1,713,598 tracked). Next came American Airlines with 1.31% (28,649 flights canceled out of 2,177,418 tracked). United Airlines canceled 26,704 out of 1,619,100 flights, for a rate of 1.65%.
When calculating on-time performance, Cirium tracks more than 35 million flights globally per year and uses a complex methodology that factors in delays and cancellations as well as passenger volume. For example, instead of simply tallying the number of delayed flights, it considers the number of passengers affected by those delays and also distinguishes shorter delays from longer ones.
While delays are indeed a key indicator of airline reliability, it’s an open secret that airlines pad their schedules—known as “schedule creep.” Even infrequent flyers will notice that very often their flight arrives ahead of schedule. That’s because carriers typically bake plenty of extra time into schedules to hedge against unforeseen hiccups. Schedule creep has been happening for many years, as detailed in this excellent BBC News explainer from 2019.
The practice of padding improves carriers’ on-time records on paper and, crucially, helps them avoid doling out expensive passenger reimbursements, which kick in when a flight delay hits the dreaded three-hour mark. Last month, the U.S. Department of Transportation (DOT) proposed new rules that would require airlines to compensate passengers between $200 and $775 for significant flight delays and cancellations that are caused by something within the carrier’s control, like a technology snafu.
Of course, many factors are outside of an airline’s control—including weather. In December 2022, Winter Storm Elliott caused massive travel disruptions across the country. But while most airlines recovered relatively quickly, Southwest’s crew-scheduling system buckled, leading to nearly 17,000 cancellations over nine days and stranding more than 2 million passengers during the peak holiday season. That month, Southwest clocked a dismal 14.6% cancellation rate.
Southwest’s hometown paper of record, The Dallas Morning News, disparaged the company as a “technological Luddite,” noting that it had only recently switched from paper to electronic reporting and still used an old-school point-to-point network instead of the hub-and-spoke model favored by other large U.S. airlines. The story piled on anecdotes from decades past, like how Southwest had used plastic boarding position markers until 2002, when post-9/11 airport security changes forced it to change.
Southwest paid dearly for its sins, and not just in the court of public opinion. The U.S. Transportation Department ordered Southwest to pay a $140 million civil penalty, by far the largest the DOT had ever levied for consumer protection violations. And that was in addition to $600 million in refunds and reimbursements that Southwest paid to travelers who faced disruptions. In total, the airline shelled out more than $750 million for the debacle.
That proved to be a wake-up call. Southwest conceded that it hadn’t invested enough in backend, non-consumer-facing technology and soon committed to spend over $1.3 billion toward upgrades and maintenance of its IT systems in 2023. The next year, another $1.7 billion was earmarked.
Cirium’s report credits Southwest for investing wisely, ensuring, among other things, that the meltdown of 2022 won’t happen again. “Southwest invested in new recovery system that improves crew communications and in minutes develops an efficient plan, so a three- or four-day disruption is limited to a single day,” wrote Scott McCartney, an aviation consultant and adjunct professor at Duke University.
Cancellation rates can vary month to month, notes Malik, adding that in June 2024, Southwest achieved an impressively low cancellation rate of just 0.3%. “These fluctuations underscore how external and operational factors can impact performance over time,” he says.
In 2024, the industry’s overall cancellation rate was slightly higher than the 1.29% recorded the previous year. Malik says that was “due to extreme weather conditions and the major IT outage experienced by many airlines.”
He’s talking, of course, about how a faulty Crowdstrike software update prompted a global outage for Microsoft Windows in July. Of all the airlines impacted by the event, Delta was hit the hardest, with more than 5,000 flight cancellations over five days—a higher number than the airline had seen in all of 2019. The company has estimated its loss from this event to be $500 million.
Yet, somehow, Southwest escaped unscathed. In the immediate aftermath of the event, it was reported (including here and here and here), and then spread widely on social media, that this was because Southwest was still using an archaic version of Microsoft Windows that had never received the problematic CrowdStrike update. The theory was that Southwest’s crusty technology had inadvertently saved it from catastrophe.
But Southwest pushed back hard on that narrative, with a spokesperson telling Forbes in August that the carrier had sidestepped the debacle because it mainly used a CrowdStrike competitor for endpoint cyber security protection and that its investments toward modernizing its core operation technology had provided additional options to vendors that were experiencing issues with the outage.
Cirium’s data is a vindication of Southwest’s investment and efforts in recent years.