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Flight Reliability

WN 991 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 991 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

86%
Arrive within 15 minutes
3 min early
Average arrival delay
2.7%
Cancelled
8 min early
Median arrival delay

Based on 364 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon87%(52 flights)
  • Tue94%(51 flights)
  • Wed96%(51 flights)
  • Thu83%(54 flights)
  • Fri71%(51 flights)
  • Sat95%(43 flights)
  • Sun78%(50 flights)
On-time by departure window
  • 3–6 AM92%(37 flights)
  • 6–9 AM93%(123 flights)
  • 9 AM–12 PM87%(87 flights)
  • 12–3 PM64%(42 flights)
  • 3–6 PM—(8 flights)
  • 9 PM–12 AM82%(55 flights)
On-time trend by month
81%
May

Jun 74% → May 81% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202574%27
July 202573%30
August 202594%31
September 2025100%30
October 202573%30
November 202590%30
December 202584%31
January 202693%29
February 202694%34
March 202691%22
April 202685%27
May 202681%31
Departures on time
83%
Diverted
0.5%
Flights flown
352
Months covered
12

Keep nerding

Based on 364 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.