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Flight Reliability

WN 4039 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 4039 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

72%
Arrive within 15 minutes
12 min
Average arrival delay
0%
Cancelled
1 min
Median arrival delay

Based on 308 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon67%(49 flights)
  • Tue73%(30 flights)
  • Wed69%(29 flights)
  • Thu69%(48 flights)
  • Fri63%(48 flights)
  • Sat88%(42 flights)
  • Sun74%(62 flights)
On-time by departure window
  • 6–9 AM91%(125 flights)
  • 9 AM–12 PM—(6 flights)
  • 12–3 PM69%(32 flights)
  • 3–6 PM50%(64 flights)
  • 6–9 PM61%(80 flights)
  • 9 PM–12 AM—(1 flights)
On-time trend by month
61%
May

Jun 91% → May 61% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202591%32
July 202583%35
August 202565%20
September 202571%17
October 202529%17
November 202563%27
December 202545%29
January 202689%18
February 202696%23
March 202686%29
April 202670%30
May 202661%31
Departures on time
68%
Diverted
0%
Flights flown
308
Months covered
12

Keep nerding

Based on 308 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.