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Flight Reliability

WN 1221 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 1221 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

73%
Arrive within 15 minutes
9 min
Average arrival delay
1.3%
Cancelled
0 min
Median arrival delay

Based on 472 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon68%(74 flights)
  • Tue81%(64 flights)
  • Wed84%(55 flights)
  • Thu77%(65 flights)
  • Fri68%(71 flights)
  • Sat66%(64 flights)
  • Sun69%(72 flights)
On-time by departure window
  • 6–9 AM93%(61 flights)
  • 9 AM–12 PM78%(72 flights)
  • 12–3 PM75%(134 flights)
  • 3–6 PM72%(90 flights)
  • 6–9 PM52%(81 flights)
  • 9 PM–12 AM67%(27 flights)
On-time trend by month
57%
May

Jun 58% → May 57% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202558%24
July 202562%26
August 202548%29
September 202572%29
October 202588%43
November 202567%52
December 202575%56
January 202692%50
February 202686%58
March 202665%37
April 202668%31
May 202657%30
Departures on time
68%
Diverted
0.2%
Flights flown
465
Months covered
12

Keep nerding

Based on 472 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.