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Flight Reliability

WN 3121 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 3121 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

76%
Arrive within 15 minutes
7 min
Average arrival delay
0.5%
Cancelled
1 min early
Median arrival delay

Based on 393 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon77%(61 flights)
  • Tue85%(48 flights)
  • Wed80%(50 flights)
  • Thu62%(66 flights)
  • Fri77%(61 flights)
  • Sat71%(35 flights)
  • Sun81%(68 flights)
On-time by departure window
  • 6–9 AM93%(107 flights)
  • 9 AM–12 PM—(1 flights)
  • 12–3 PM76%(41 flights)
  • 3–6 PM61%(104 flights)
  • 6–9 PM64%(90 flights)
  • 9 PM–12 AM96%(46 flights)
On-time trend by month
96%
May

Jun 59% → May 96% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202559%34
July 202548%40
August 202582%55
September 202568%57
October 202557%30
November 202596%25
December 2025100%20
January 202668%28
February 202677%17
March 202697%30
April 202696%27
May 202696%26
Departures on time
70%
Diverted
0.5%
Flights flown
389
Months covered
12

Keep nerding

Based on 393 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.