Carrier route record
ASPHX→SEA
Alaska Airlines · Phoenix to Seattle
- Flights
- 2,886
- Period
- September 2025 to August 2026
- Share of route
- 40%
- Carriers
- 7
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on PHX to SEA earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 2,886 flights. The strongest carrier on the route with a full sample, Envoy Air, flew 761 at 87.6% on time.
Envoy Air is the most reliable of the four carriers covered here at 87.6% on time across 761 flights.
Key figures
On time
84.4%
Arrivals under 15 minutes late, of 2,861 completed flights
Avg delay
56 min
Across delayed arrivals only, not all flights
Cancelled
0.76%
National rate is 1.89%
Whole route
82.2%
Every carrier on PHX to SEA, 7,202 flights
These figures cover 2,886 flights between September 2025 and August 2026. The median arrival is 7 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Carrier by carrier
Alaska against every carrier on PHX to SEA
Alaska flew 2,886 of the 7,202 flights on PHX to SEA, about 40% of it. Its 84.4% on time is 2 points better than the route as a whole, which runs 82.2%. Ranked by on-time rate it is number three of seven carriers on the route, where the range runs from Envoy at 87.6% to Southwest at 62.2%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. Envoy Air arrives on time 87.6% of the time; Southwest Airlines manages 62.2%. Sample sizes sit next to every figure, because a two-point gap across 1,039 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Envoy Air | 761 | 87.6% | 50 min | 0.00% | A+ |
| Delta Air Lines | 1,767 | 87.5% | 75 min | 0.96% | A+ |
| Alaska Airlines (this page) | 2,886 | 84.4% | 56 min | 0.76% | B+ |
| Frontier Airlinesthin sample | 116 | 83.6% | 83 min | 0.00% | B+ |
| SkyWest Airlines | 409 | 83.0% | 63 min | 0.49% | B+ |
| American Airlinesthin sample | 224 | 82.5% | 63 min | 0.45% | B+ |
| Southwest Airlines | 1,039 | 62.2% | 45 min | 0.77% | D+ |
The spread between Envoy and Southwest is 25 points, wide enough that it should decide the booking. On a hundred trips that is 25 more arrivals inside the on-time window.
Flight by flight
Alaska flight numbers on PHX to SEA
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Departure window
When Alaska runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 2,886 flights.
- 5am–8am587 flights88.7%
- 8am–11am533 flights80.4%
- 11am–2pm557 flights87.7%
- 2pm–5pm621 flights81.4%
- 5pm–8pm462 flights84.2%
- 8pm–5am126 flights82.9%
Scale runs 70% to 95%.
Book the early departure. Flights leaving between 5am–8am arrive on time 88.7% of the time, against 80.4% for the morning window. That is 8 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 621 flights scheduled in it.
Across the year
Alaska on PHX to SEA through the year
July is the worst month at 72.0% on time, 21 points below May, the best at 93.4%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. April was the busiest month here, with 303 flights.
Across the week, Sunday is the strongest day at 86.9% on time and Thursday the weakest at 81.2%, a spread of 6 points.
Arrival by arrival
How late Alaska on PHX to SEA runs when it is late
Alaska on PHX to SEA often beats the schedule: 807 of 2,861 completed flights, 28%, arrived 15 minutes or more early. The 446 late arrivals split 205 under half an hour, 143 between 30 and 60 minutes, and 98 an hour or more.
- 15+ min early807 flights28.2%
- Within 15 min1,608 flights56.2%
- 15–29 min late205 flights7.2%
- 30–59 min late143 flights5.0%
- 1–2 hours late52 flights1.8%
- 2+ hours late46 flights1.6%
Scale runs 0% to 100%.
Share of 2,861 completed flights by arrival against schedule.
108 of 430 late departures made up the time and arrived on time, 25% of them. 124 flights left on time and still arrived late.
The worst days
Worst days for Alaska on PHX to SEA
The latest arrival of the period was on 26 January 2026, 9 hours 41 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The five worst days are spread across January, June, March and September, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 26 January 2026 | 9 hours 41 minutes | Late-arriving aircraft |
| 2 June 2026 | 8 hours 45 minutes | Carrier |
| 13 March 2026 | 7 hours 16 minutes | Extreme weather |
| 26 September 2025 | 7 hours 11 minutes | Late-arriving aircraft |
| 13 March 2026 | 7 hours | Extreme weather |
Delay causes
Why Alaska runs late on this route
Late-arriving aircraft accounts for 45% of the 25,000 delay minutes carriers reported here, and the remaining four split what is left.
- 45%Late-arriving aircraft
- 30%Carrier
- 20%National Airspace System
- 5%Extreme weather
- 0%Security
45% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 25,000 reported delay minutes here, that single category outweighs weather by 9 to one. The split is drawn from 24,903 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 88.7% on time here.
Cancellations are rare at 0.76%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 3.4% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 1,107 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg is a different operation and performs like one: it runs 79.2% on time across 2,889 flights, 5 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 5 points of difference.
The sample behind these figures is 2,886 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking Alaska on PHX to SEA
Put together: the calendar is the biggest lever here, not the carrier or the hour. May runs 93.4% on time and July 72.0%, a swing of 21 points. If the dates move at all, move them out of July before you think about anything else. 2,861 completed flights over 12 months sit behind that.
Related
Where to go next
- PHX to SEA, every carrier
- Alaska on SEA to PHX, the return leg
- Envoy Air on PHX to SEA87.6%
- Delta Air Lines on PHX to SEA87.5%
- Frontier Airlines on PHX to SEA83.6%
- SkyWest Airlines on PHX to SEA83.0%
- American Airlines on PHX to SEA82.5%
- Southwest Airlines on PHX to SEA62.2%
- Alaska Airlines network-wide record
- Phoenix Sky Harbor International (PHX) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Why the first flight of the morning is statistically safest
- Same route, different airline: where the carrier you pick matters most
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.