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WanderNerd

Flight Reliability

WN 3971 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 3971 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
20 min
Average arrival delay
1.8%
Cancelled
3 min
Median arrival delay

Based on 384 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon69%(65 flights)
  • Tue78%(37 flights)
  • Wed63%(35 flights)
  • Thu69%(64 flights)
  • Fri57%(68 flights)
  • Sat67%(49 flights)
  • Sun75%(57 flights)
On-time by departure window
  • 3–6 AM(1 flights)
  • 6–9 AM91%(11 flights)
  • 9 AM–12 PM82%(93 flights)
  • 12–3 PM88%(17 flights)
  • 3–6 PM61%(111 flights)
  • 6–9 PM58%(134 flights)
  • 9 PM–12 AM(8 flights)
On-time trend by month
87%
May

Jun 80% → May 87% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202580%35
July 202569%32
August 202560%30
September 202547%30
October 202567%42
November 202566%41
December 202582%34
March 202654%52
April 202671%35
May 202687%31
Departures on time
68%
Diverted
0.5%
Flights flown
375
Months covered
12

Based on 384 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.