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Flight Reliability

WN 603 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 603 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
6 min
Average arrival delay
0.9%
Cancelled
4 min early
Median arrival delay

Based on 344 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon74%(49 flights)
  • Tue80%(44 flights)
  • Wed81%(43 flights)
  • Thu73%(48 flights)
  • Fri69%(48 flights)
  • Sat95%(43 flights)
  • Sun65%(65 flights)
On-time by departure window
  • 3–6 AM—(2 flights)
  • 6–9 AM93%(56 flights)
  • 9 AM–12 PM90%(41 flights)
  • 12–3 PM75%(56 flights)
  • 3–6 PM80%(109 flights)
  • 6–9 PM49%(76 flights)
On-time trend by month
35%
May

Jun 77% → May 35% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202577%30
July 202587%30
August 202587%38
September 202584%38
October 202594%35
November 202559%29
December 202571%28
January 202673%11
February 202679%19
March 202690%29
April 202656%27
May 202635%26
Departures on time
71%
Diverted
0.3%
Flights flown
340
Months covered
12

Keep nerding

Based on 344 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.