Skip to content
WanderNerd
Check a flight

Flight Reliability

WN 4377 · Southwest Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and WN 4377 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

80%
Arrive within 15 minutes
1 min
Average arrival delay
0%
Cancelled
8 min early
Median arrival delay

Based on 179 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon83%(29 flights)
  • Tue85%(20 flights)
  • Wed91%(21 flights)
  • Thu87%(31 flights)
  • Fri78%(27 flights)
  • Sat81%(21 flights)
  • Sun63%(30 flights)
On-time by departure window
  • 6–9 AM96%(56 flights)
  • 12–3 PM96%(25 flights)
  • 3–6 PM66%(58 flights)
  • 6–9 PM70%(40 flights)
On-time trend by month
93%
May

Aug 64% → May 93% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
August 202564%28
September 202577%30
November 202591%11
December 2025100%16
February 202672%18
March 202676%33
April 202694%17
May 202693%14
Departures on time
78%
Diverted
0%
Flights flown
179
Months covered
10

Keep nerding

Based on 179 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.