Carrier route record
ASSEA→PHX
Alaska Airlines · Seattle to Phoenix
- Flights
- 2,889
- 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 SEA to PHX lands a B+, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 45 minutes on average. That rests on 2,889 flights. The strongest carrier on the route with a full sample, Envoy Air, flew 760 at 85.3% on time.
Envoy Air is the most reliable of the four carriers covered here at 85.3% on time across 760 flights.
Key figures
On time
79.2%
Arrivals under 15 minutes late, of 2,862 completed flights
Avg delay
45 min
Across delayed arrivals only, not all flights
Cancelled
0.66%
National rate is 1.89%
Whole route
78.2%
Every carrier on SEA to PHX, 7,205 flights
These figures cover 2,889 flights between September 2025 and August 2026. The median arrival is 5 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 SEA to PHX
Alaska flew 2,889 of the 7,205 flights on SEA to PHX, about 40% of it. Its 79.2% on time is about level with the route as a whole at 78.2%. Ranked by on-time rate it is number four of seven carriers on the route, where the range runs from Envoy at 85.3% to Southwest at 65.1%. 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 85.3% of the time; Southwest Airlines manages 65.1%. Sample sizes sit next to every figure, because a two-point gap across 1,042 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Envoy Air | 760 | 85.3% | 74 min | 0.00% | A+ |
| American Airlinesthin sample | 221 | 83.2% | 76 min | 0.45% | B+ |
| Delta Air Lines | 1,768 | 80.9% | 67 min | 0.96% | B+ |
| Alaska Airlines (this page) | 2,889 | 79.2% | 45 min | 0.66% | B+ |
| SkyWest Airlines | 409 | 78.5% | 80 min | 0.49% | B+ |
| Frontier Airlinesthin sample | 116 | 74.5% | 146 min | 5.17% | C− |
| Southwest Airlines | 1,042 | 65.1% | 49 min | 0.77% | C+ |
The spread between Envoy and Southwest is 20 points, wide enough that it should decide the booking. On a hundred trips that is 20 more arrivals inside the on-time window.
Flight by flight
Alaska flight numbers on SEA to PHX
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Departure window
When Alaska runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 16 points, against 20 points between the best and worst carrier.
- 5am–8am321 flights90.2%
- 8am–11am553 flights82.8%
- 11am–2pm521 flights74.3%
- 2pm–5pm571 flights80.5%
- 5pm–8pm511 flights76.2%
- 8pm–5am412 flights73.8%
Scale runs 65% to 95%.
Book the early departure. Flights leaving between 5am–8am arrive on time 90.2% of the time, against 73.8% for the overnight window. That is 16 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 571 flights scheduled in it.
Across the year
Alaska on SEA to PHX through the year
July is the worst month at 60.7% on time, 28 points below April, the best at 89.0%. 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. March was the busiest month here, with 301 flights.
Across the week, Tuesday is the strongest day at 86.0% on time and Sunday the weakest at 74.0%, a spread of 12 points.
Arrival by arrival
How late Alaska on SEA to PHX runs when it is late
Alaska on SEA to PHX often beats the schedule: 763 of 2,862 completed flights, 27%, arrived 15 minutes or more early. The 596 late arrivals split 268 under half an hour, 219 between 30 and 60 minutes, and 109 an hour or more.
- 15+ min early763 flights26.7%
- Within 15 min1,503 flights52.5%
- 15–29 min late268 flights9.4%
- 30–59 min late219 flights7.7%
- 1–2 hours late84 flights2.9%
- 2+ hours late25 flights0.9%
Scale runs 0% to 100%.
Share of 2,862 completed flights by arrival against schedule.
164 of 615 late departures made up the time and arrived on time, 27% of them. In the other direction, 145 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at PHX.
The worst days
Worst days for Alaska on SEA to PHX
The latest arrival of the period was on 23 October 2025, 6 hours behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 23 October 2025 | 6 hours | Carrier |
| 26 October 2025 | 4 hours 59 minutes | Carrier |
| 8 June 2026 | 4 hours 46 minutes | Carrier |
| 13 March 2026 | 4 hours 26 minutes | Late-arriving aircraft |
| 16 July 2026 | 4 hours 5 minutes | National Airspace System |
Delay causes
Why Alaska runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 27,000 reported delay minutes.
- 37%Carrier
- 33%Late-arriving aircraft
- 29%National Airspace System
- 1%Extreme weather
- 0%Security
The largest share of delay minutes, 37%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 9,855 of the 27,000 delay minutes reported here. The split is drawn from 26,500 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 90.2% on time here.
Cancellations are rare at 0.66%, 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 3.8% 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 84.4% on time across 2,886 flights, 5 points above 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 2,889 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 SEA to PHX
Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 89.0% on time and July 60.7%, a swing of 28 points. If the dates move at all, move them out of July before you think about anything else. 2,862 completed flights over 12 months sit behind that.
Related
Where to go next
- SEA to PHX, every carrier
- Alaska on PHX to SEA, the return leg
- Envoy Air on SEA to PHX85.3%
- American Airlines on SEA to PHX83.2%
- Delta Air Lines on SEA to PHX80.9%
- SkyWest Airlines on SEA to PHX78.5%
- Frontier Airlines on SEA to PHX74.5%
- Southwest Airlines on SEA to PHX65.1%
- Alaska Airlines network-wide record
- Seattle-Tacoma International (SEA) delay statistics
- Phoenix Sky Harbor International (PHX) 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.