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Flight Reliability

WN 1638 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 1638 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

84%
Arrive within 15 minutes
3 min
Average arrival delay
0.6%
Cancelled
4 min early
Median arrival delay

Based on 362 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon83%(52 flights)
  • Tue80%(51 flights)
  • Wed84%(51 flights)
  • Thu85%(52 flights)
  • Fri85%(52 flights)
  • Sat91%(44 flights)
  • Sun83%(58 flights)
On-time by departure window
  • 3–6 AM96%(45 flights)
  • 6–9 AM92%(122 flights)
  • 9 AM–12 PM94%(17 flights)
  • 12–3 PM81%(74 flights)
  • 3–6 PM71%(78 flights)
  • 6–9 PM71%(24 flights)
On-time trend by month
100%
May

Jun 86% → May 100% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202586%35
July 202582%39
August 202582%34
September 202582%34
October 202568%31
November 202597%29
December 202581%31
January 202687%31
February 202686%28
March 202677%31
April 202695%19
May 2026100%18
Departures on time
85%
Diverted
0%
Flights flown
360
Months covered
12

Keep nerding

Based on 362 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.