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Flight Reliability

WN 1855 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 1855 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

78%
Arrive within 15 minutes
7 min
Average arrival delay
0.3%
Cancelled
4 min early
Median arrival delay

Based on 385 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon78%(60 flights)
  • Tue92%(51 flights)
  • Wed85%(52 flights)
  • Thu66%(62 flights)
  • Fri70%(57 flights)
  • Sat90%(30 flights)
  • Sun72%(72 flights)
On-time by departure window
  • 3–6 AM93%(14 flights)
  • 6–9 AM—(5 flights)
  • 9 AM–12 PM91%(74 flights)
  • 12–3 PM77%(111 flights)
  • 3–6 PM81%(97 flights)
  • 6–9 PM62%(76 flights)
  • 9 PM–12 AM—(7 flights)
On-time trend by month
78%
May

Jun 57% → May 78% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202557%30
July 202558%31
August 202577%30
September 202580%30
October 202587%31
November 202597%37
December 202581%42
January 202681%32
February 202674%42
March 202679%34
April 202677%22
May 202678%23
Departures on time
73%
Diverted
0%
Flights flown
384
Months covered
12

Keep nerding

Based on 385 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.