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WanderNerd

Flight Reliability

WN 4640 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 4640 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

85%
Arrive within 15 minutes
1 min early
Average arrival delay
1.2%
Cancelled
6 min early
Median arrival delay

Based on 169 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon83%(24 flights)
  • Tue100%(21 flights)
  • Wed100%(18 flights)
  • Thu87%(23 flights)
  • Fri81%(26 flights)
  • Sat77%(26 flights)
  • Sun76%(29 flights)
On-time by departure window
  • 3–6 AM97%(32 flights)
  • 6–9 AM95%(58 flights)
  • 9 AM–12 PM76%(49 flights)
  • 12–3 PM80%(15 flights)
  • 3–6 PM(5 flights)
  • 6–9 PM(8 flights)
On-time trend by month
74%
May

Oct 93% → May 74% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
October 202593%30
December 202564%11
February 202694%18
March 202696%28
April 202683%30
May 202674%31
Departures on time
83%
Diverted
0%
Flights flown
167
Months covered
9

Based on 169 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.