Starting from 0.8% in 2012, Southwest's flight cancellation rate had tripled to 2.4% by 2022. The airline had also had higher cancellation rates than other major airlines. Meanwhile, their flight on time rate had slid to its lowest level in 10 years.

Southwest Airlines historically maintains a relatively stable operational record, but like all major carriers, it faces fluctuations due to weather and technical events. On a "typical" day in 2026, Southwest’s cancellation rate usually hovers around 1% to 2%, which is standard for the U.S. domestic market. However, during major disruptions—such as "Winter Storm Fern" in early 2026—cancellations can spike to 7% or higher as the airline proactively ramps down operations for safety. Delay frequencies are more common, with roughly 15% to 25% of flights experiencing some form of arrival delay during peak seasons or at high-traffic hubs like Midway or Denver. Following its massive "business transformation" in 2025, Southwest has invested heavily in new scheduling technology and aircraft (ending 2025 with a fleet of 803 jets) to improve reliability. Despite these efforts, last-minute disruptions remain a reality, though the airline was notably ranked as the #1 "Best U.S. Airline" by the Wall Street Journal in 2025 for its hospitality and overall operational excellence.