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WanderNerd

Flight Reliability

WN 3998 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 3998 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

71%
Arrive within 15 minutes
15 min
Average arrival delay
1.7%
Cancelled
1 min
Median arrival delay

Based on 233 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon76%(33 flights)
  • Tue89%(28 flights)
  • Wed83%(29 flights)
  • Thu71%(34 flights)
  • Fri66%(35 flights)
  • Sat66%(32 flights)
  • Sun54%(37 flights)
On-time by departure window
  • 9 AM–12 PM(5 flights)
  • 12–3 PM78%(106 flights)
  • 3–6 PM76%(21 flights)
  • 6–9 PM63%(54 flights)
  • 9 PM–12 AM57%(42 flights)
On-time trend by month
52%
May

Jun 72% → May 52% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202572%25
July 202559%32
August 202585%27
September 202592%26
October 202570%43
March 202676%25
April 202662%21
May 202652%23
Departures on time
66%
Diverted
0.4%
Flights flown
228
Months covered
11

Based on 233 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.