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Flight Reliability

WN 1851 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 1851 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
9 min
Average arrival delay
0.5%
Cancelled
4 min early
Median arrival delay

Based on 424 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon72%(64 flights)
  • Tue91%(66 flights)
  • Wed87%(68 flights)
  • Thu72%(64 flights)
  • Fri74%(57 flights)
  • Sat71%(52 flights)
  • Sun61%(51 flights)
On-time by departure window
  • 6–9 AM92%(13 flights)
  • 9 AM–12 PM82%(66 flights)
  • 12–3 PM83%(123 flights)
  • 3–6 PM63%(130 flights)
  • 6–9 PM51%(35 flights)
  • 9 PM–12 AM96%(55 flights)
On-time trend by month
100%
May

Jun 53% → May 100% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202553%34
July 202555%33
August 202575%16
September 2025100%13
October 202569%26
November 202570%43
December 202578%49
January 202682%28
February 202682%27
March 202679%81
April 202683%41
May 2026100%31
Departures on time
72%
Diverted
0%
Flights flown
422
Months covered
12

Keep nerding

Based on 424 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.