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Flight Reliability

WN 556 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 556 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

79%
Arrive within 15 minutes
6 min
Average arrival delay
1.7%
Cancelled
2 min early
Median arrival delay

Based on 518 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon85%(74 flights)
  • Tue78%(89 flights)
  • Wed83%(87 flights)
  • Thu74%(74 flights)
  • Fri86%(72 flights)
  • Sat68%(37 flights)
  • Sun72%(75 flights)
On-time by departure window
  • 3–6 AM92%(13 flights)
  • 6–9 AM90%(49 flights)
  • 9 AM–12 PM87%(86 flights)
  • 12–3 PM85%(117 flights)
  • 3–6 PM75%(143 flights)
  • 6–9 PM62%(98 flights)
  • 9 PM–12 AM—(2 flights)
On-time trend by month
85%
May

Jun 80% → May 85% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202580%66
July 202565%75
August 202571%41
September 202597%39
October 202565%48
November 202579%28
December 202587%31
January 202679%33
February 202682%39
March 202690%31
April 202684%38
May 202685%39
Departures on time
76%
Diverted
0.2%
Flights flown
508
Months covered
12

Keep nerding

Based on 518 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.