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Flight Reliability

WN 420 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 420 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

85%
Arrive within 15 minutes
2 min
Average arrival delay
0.5%
Cancelled
5 min early
Median arrival delay

Based on 378 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon84%(55 flights)
  • Tue86%(49 flights)
  • Wed85%(47 flights)
  • Thu79%(53 flights)
  • Fri91%(55 flights)
  • Sat87%(63 flights)
  • Sun83%(53 flights)
On-time by departure window
  • 3–6 AM—(1 flights)
  • 6–9 AM100%(71 flights)
  • 9 AM–12 PM90%(67 flights)
  • 12–3 PM73%(126 flights)
  • 3–6 PM76%(41 flights)
  • 6–9 PM90%(51 flights)
  • 9 PM–12 AM100%(18 flights)
On-time trend by month
85%
May

Jun 100% → May 85% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 2025100%34
July 202597%31
August 202585%26
September 202585%26
October 202577%31
November 202592%38
December 202598%44
January 202683%35
February 202657%28
March 202668%31
April 202684%25
May 202685%26
Departures on time
78%
Diverted
0.3%
Flights flown
375
Months covered
12

Keep nerding

Based on 378 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.