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WanderNerd

Flight Reliability

WN 3957 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 3957 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

80%
Arrive within 15 minutes
4 min
Average arrival delay
0.4%
Cancelled
9 min early
Median arrival delay

Based on 236 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon73%(26 flights)
  • Tue94%(36 flights)
  • Wed79%(34 flights)
  • Thu75%(28 flights)
  • Fri83%(35 flights)
  • Sat91%(32 flights)
  • Sun64%(44 flights)
On-time by departure window
  • 3–6 AM97%(38 flights)
  • 6–9 AM94%(67 flights)
  • 9 AM–12 PM100%(18 flights)
  • 12–3 PM(1 flights)
  • 3–6 PM74%(49 flights)
  • 6–9 PM50%(42 flights)
  • 9 PM–12 AM60%(20 flights)
On-time trend by month
100%
May

Jun 75% → May 100% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202575%16
July 202568%25
August 202589%27
September 2025100%30
October 202523%13
November 202561%18
December 202567%15
February 202675%20
March 202670%10
April 202692%26
May 2026100%31
Departures on time
76%
Diverted
0%
Flights flown
235
Months covered
12

Based on 236 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.