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WanderNerd

Flight Reliability

WN 3996 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 3996 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

77%
Arrive within 15 minutes
5 min
Average arrival delay
0.8%
Cancelled
3 min early
Median arrival delay

Based on 261 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon72%(39 flights)
  • Tue67%(36 flights)
  • Wed79%(38 flights)
  • Thu78%(41 flights)
  • Fri77%(44 flights)
  • Sat100%(17 flights)
  • Sun80%(44 flights)
On-time by departure window
  • 6–9 AM95%(95 flights)
  • 9 AM–12 PM61%(23 flights)
  • 12–3 PM63%(24 flights)
  • 3–6 PM71%(80 flights)
  • 6–9 PM65%(37 flights)
On-time trend by month
73%
May

Aug 63% → May 73% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
August 202563%27
September 202560%30
November 202593%28
December 2025100%30
February 202664%14
March 202667%24
April 202685%47
May 202673%52
Departures on time
75%
Diverted
0%
Flights flown
259
Months covered
11

Based on 261 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.