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Flight Reliability

WN 3966 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 3966 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

83%
Arrive within 15 minutes
2 min
Average arrival delay
0.3%
Cancelled
6 min early
Median arrival delay

Based on 295 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon78%(45 flights)
  • Tue79%(42 flights)
  • Wed85%(39 flights)
  • Thu84%(45 flights)
  • Fri85%(48 flights)
  • Sat94%(36 flights)
  • Sun76%(37 flights)
On-time by departure window
  • 3–6 AM—(4 flights)
  • 6–9 AM89%(151 flights)
  • 9 AM–12 PM96%(23 flights)
  • 12–3 PM86%(21 flights)
  • 3–6 PM49%(37 flights)
  • 6–9 PM—(9 flights)
  • 9 PM–12 AM83%(47 flights)
On-time trend by month
82%
May

Jun 92% → May 82% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202592%24
July 202582%28
October 202542%33
November 202582%28
December 202586%29
January 202694%33
February 202694%36
March 202688%25
April 202689%26
May 202682%27
Departures on time
81%
Diverted
0.7%
Flights flown
292
Months covered
11

Keep nerding

Based on 295 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.