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Flight Reliability

WN 851 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 851 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

76%
Arrive within 15 minutes
11 min
Average arrival delay
1.2%
Cancelled
0 min
Median arrival delay

Based on 340 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon80%(35 flights)
  • Tue79%(56 flights)
  • Wed79%(56 flights)
  • Thu72%(36 flights)
  • Fri74%(38 flights)
  • Sat78%(60 flights)
  • Sun67%(55 flights)
On-time by departure window
  • 3–6 AM—(2 flights)
  • 6–9 AM84%(74 flights)
  • 9 AM–12 PM86%(56 flights)
  • 12–3 PM83%(90 flights)
  • 3–6 PM60%(102 flights)
  • 6–9 PM50%(12 flights)
On-time trend by month
24%
May

Jun 81% → May 24% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202581%26
July 202566%29
August 202590%29
September 202583%29
October 202584%31
November 202583%29
December 202584%31
January 202683%30
February 202677%26
March 202666%38
April 202667%21
May 202624%17
Departures on time
72%
Diverted
0%
Flights flown
336
Months covered
12

Keep nerding

Based on 340 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.