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Flight Reliability

WN 4155 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 4155 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

66%
Arrive within 15 minutes
13 min
Average arrival delay
0.3%
Cancelled
3 min
Median arrival delay

Based on 334 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon70%(56 flights)
  • Tue76%(46 flights)
  • Wed78%(46 flights)
  • Thu54%(56 flights)
  • Fri71%(55 flights)
  • Sat63%(19 flights)
  • Sun53%(55 flights)
On-time by departure window
  • 3–6 AM100%(14 flights)
  • 6–9 AM100%(19 flights)
  • 9 AM–12 PM80%(46 flights)
  • 12–3 PM50%(82 flights)
  • 3–6 PM64%(91 flights)
  • 6–9 PM64%(80 flights)
  • 9 PM–12 AM—(1 flights)
On-time trend by month
62%
May

Jun 55% → May 62% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202555%51
July 202536%55
August 202571%31
September 202577%26
November 202565%26
December 202569%29
March 2026100%26
April 202688%41
May 202662%42
Departures on time
60%
Diverted
0%
Flights flown
333
Months covered
11

Keep nerding

Based on 334 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.