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WanderNerd

Flight Reliability

WN 3621 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 3621 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

68%
Arrive within 15 minutes
12 min
Average arrival delay
1.0%
Cancelled
3 min
Median arrival delay

Based on 305 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon57%(44 flights)
  • Tue83%(30 flights)
  • Wed78%(32 flights)
  • Thu46%(48 flights)
  • Fri80%(46 flights)
  • Sat77%(53 flights)
  • Sun61%(49 flights)
On-time by departure window
  • 3–6 AM(7 flights)
  • 6–9 AM72%(32 flights)
  • 9 AM–12 PM71%(42 flights)
  • 12–3 PM(8 flights)
  • 3–6 PM72%(94 flights)
  • 6–9 PM62%(84 flights)
  • 9 PM–12 AM57%(35 flights)
On-time trend by month
58%
May

Jun 50% → May 58% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202550%20
July 202555%20
October 202577%30
November 202584%25
December 202595%20
March 202664%39
April 202672%60
May 202658%67
Departures on time
64%
Diverted
0%
Flights flown
302
Months covered
12

Based on 305 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.