Skip to content
WanderNerd

Flight Reliability

WN 3909 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 3909 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

64%
Arrive within 15 minutes
17 min
Average arrival delay
0.7%
Cancelled
5 min
Median arrival delay

Based on 135 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon39%(23 flights)
  • Tue89%(18 flights)
  • Wed59%(17 flights)
  • Thu60%(20 flights)
  • Fri67%(24 flights)
  • Sat60%(10 flights)
  • Sun77%(22 flights)
On-time by departure window
  • 9 AM–12 PM75%(32 flights)
  • 12–3 PM72%(43 flights)
  • 3–6 PM44%(45 flights)
  • 6–9 PM(6 flights)
  • 9 PM–12 AM(8 flights)
On-time trend by month
55%
Oct

Aug 88% → Oct 55% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
August 202588%24
September 202565%26
October 202555%47
Departures on time
58%
Diverted
0%
Flights flown
134
Months covered
12

Based on 135 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.