Skip to content
WanderNerd
Check a flight

Flight Reliability

AS 604 · Alaska Airlines

Seattle → Phoenix (SEA–PHX)83% of its flights flew this route. The rest (PIT–SEA) are included in these numbers.

90
Nerd Approved
WanderNerd Reliability Score
87%
Arrive within 15 minutes
3 min early
Average arrival delay
1.2%
Cancelled
11 min early
Median arrival delay

Based on 255 historical flights. Data through May 2026.

What the data says

Sunday scaries are real for this one.

AS 604 arrived on time 92% of the time on Wednesdays. On Sundays: 78%.

A bit ahead of the SEA–PHX route.

AS 604 arrived on time 87% of the time, versus 80% across the SEA–PHX route.

A bit ahead of the Alaska Airlines network.

AS 604 arrived on time 87% of the time, versus 80% across the Alaska Airlines network.

Slipping a little lately.

AS 604 arrived on time 85% of the time over the last three months in the data, compared with 90% in the three months before that.

The breakdown

On-time by weekday
  • Mon87%(37 flights)
  • Tue86%(36 flights)
  • Wed92%(37 flights)
  • Thu90%(30 flights)
  • Fri87%(37 flights)
  • Sat88%(34 flights)
  • Sun78%(41 flights)
On-time by departure window
  • 6–9 AM87%(212 flights)
  • 6–9 PM85%(40 flights)
On-time trend by month
81%
May

Jun 73% → May 81% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202573%15
August 202591%11
September 202591%22
October 202587%30
November 202586%29
December 202589%28
February 202694%17
March 202680%30
April 202693%30
May 202681%31
Departures on time
88%
Diverted
0%
Flights flown
252
Months covered
12

Same route, other flights

Keep nerding

Based on 255 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.