Southwest Airlines

What the Data Says About Southwest Airlines

Across 7,582,834 flights reported to the Bureau of Transportation Statistics between 2020 and 2025, Southwest Airlines (WN) posted a 80.4% on-time rate, with 1,487,141 delayed departures and 181,898 cancellations. The carrier's average delay when flights run late is 57.9 minutes, and its cancellation rate of 2.40% sits alongside an overall delay rate of 19.6%. Those baseline numbers frame every comparison you can make with other carriers in the BTS dataset.

Digging into causes, Late Aircraft drives the biggest share of minutes lost, with Late Aircraft accounting for 49.9% of delay time and Carrier contributing 30.9%. Weather — often blamed informally — represents 2.4% of total delay minutes, while National Aviation System constraints such as air traffic control and airspace congestion make up 16.6%. Security delays remain the smallest bucket at 0.3%. Taken together, operational and scheduling factors outweigh weather as the dominant driver of Southwest Airlines delays.

Seasonality matters too. Recent monthly data shows November 2024 as the best period for Southwest Airlines with a 87% on-time rate, while July 2025 was the roughest at 72% on-time — a spread of 16 percentage points between best and worst month. For passengers choosing between carriers, the combination of a 80.4% on-time rate, 57.9-minute average delay, and 2.40% cancellation rate is the clearest summary of what to expect on Southwest Airlines flights based on BTS reporting.