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Flight Reliability

AS 637 · Alaska Airlines

Phoenix → Seattle (PHX–SEA)

93
Nerd Approved
WanderNerd Reliability Score
89%
Arrive within 15 minutes
1 min early
Average arrival delay
0.6%
Cancelled
8 min early
Median arrival delay

Based on 353 historical flights. Data through May 2026.

What the data says

Morning-you made the right choice.

AS 637 departing between 9 AM–12 PM arrived on time 90% of the time, versus 75% between 12–3 PM.

Skip Thursday if you can.

AS 637 arrived on time 94% of the time on Saturdays. On Thursdays: 84%.

A bit ahead of the PHX–SEA route.

AS 637 arrived on time 89% of the time, versus 84% across the PHX–SEA route.

Better than the Alaska Airlines network average.

AS 637 arrived on time 89% of the time, versus 80% across the Alaska Airlines network.

The breakdown

On-time by weekday
  • Mon92%(50 flights)
  • Tue88%(50 flights)
  • Wed86%(49 flights)
  • Thu84%(50 flights)
  • Fri88%(51 flights)
  • Sat94%(49 flights)
  • Sun90%(51 flights)
On-time by departure window
  • 9 AM–12 PM90%(334 flights)
  • 12–3 PM75%(16 flights)
On-time trend by month
97%
May

Jun 83% → May 97% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202583%18
July 202590%31
August 202597%30
September 202586%29
October 202587%31
November 202583%30
December 202574%31
January 202694%31
February 202696%28
March 202680%30
April 202697%30
May 202697%31
Departures on time
89%
Diverted
0.3%
Flights flown
350
Months covered
12

Same route, other flights

Keep nerding

Based on 353 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.