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Flight Reliability

WN 400 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 400 moved between routes during this period. Numbers below combine all of them, so treat them as background, not a verdict. For a cleaner answer, check the route you are actually flying.

Combined across all its routes

70%
Arrive within 15 minutes
12 min
Average arrival delay
0.9%
Cancelled
2 min
Median arrival delay

Based on 351 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon67%(42 flights)
  • Tue86%(51 flights)
  • Wed85%(52 flights)
  • Thu61%(44 flights)
  • Fri57%(44 flights)
  • Sat75%(60 flights)
  • Sun57%(54 flights)
On-time by departure window
  • 6–9 AM100%(18 flights)
  • 9 AM–12 PM84%(106 flights)
  • 12–3 PM84%(37 flights)
  • 3–6 PM43%(113 flights)
  • 6–9 PM78%(73 flights)
On-time trend by month
53%
May

Jun 58% → May 53% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202558%33
July 202562%34
August 202581%21
September 2025100%17
October 202581%31
November 202563%32
December 202565%31
January 202687%31
February 202682%28
March 202667%30
April 202666%29
May 202653%30
Departures on time
66%
Diverted
0.3%
Flights flown
347
Months covered
12

Keep nerding

Based on 351 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.