Carrier route record
ASSEA→PHX
Alaska Airlines · Seattle to Phoenix
- Flights
- 2,906
- Period
- July 2025 to June 2026
- Share of route
- 40%
- Carriers
- 7
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on SEA to PHX lands a B+, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 45 minutes on average. That is a workable record, not a spotless one. That rests on 2,906 flights. The strongest carrier on the route with a full sample, Envoy Air, flew 691 at 86.9% on time.
Envoy Air is the most reliable of the four carriers covered here at 86.9% on time across 691 flights.
Key figures
On time
79.0%
Arrivals under 15 minutes late, of 2,880 completed flights
Avg delay
45 min
Across delayed arrivals only, not all flights
Cancelled
0.65%
National rate is 1.81%
Whole route
79.2%
Every carrier on SEA to PHX, 7,268 flights
These figures cover 2,906 flights between July 2025 and June 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.
Carrier by carrier
Alaska against every carrier on SEA to PHX
Alaska flew 2,906 of the 7,268 flights on SEA to PHX, about 40% of it. Its 79.0% on time is about level with the route as a whole at 79.2%. Ranked by on-time rate it is number five of seven carriers on the route, where the range runs from Envoy at 86.9% to Southwest at 69.0%. 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 86.9% of the time; Southwest Airlines manages 69.0%. Sample sizes sit next to every figure, because a two-point gap across 1,036 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Envoy Air | 691 | 86.9% | 71 min | 0.00% | A+ |
| American Airlinesthin sample | 199 | 84.8% | 81 min | 0.50% | B+ |
| Delta Air Lines | 1,765 | 82.6% | 65 min | 0.85% | B+ |
| SkyWest Airlines | 506 | 80.2% | 75 min | 0.59% | B+ |
| Alaska Airlines (this page) | 2,906 | 79.0% | 45 min | 0.65% | B+ |
| Frontier Airlinesthin sample | 165 | 70.4% | 126 min | 3.64% | C− |
| Southwest Airlines | 1,036 | 69.0% | 47 min | 0.68% | C+ |
The spread between Envoy and Southwest is 18 points, wide enough that it should decide the booking. On a hundred trips that is 18 more arrivals inside the on-time window.
Flight by flight
Alaska flight numbers on SEA to PHX
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 18 points, against 18 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am294 flights91.0%
- 8am–11am613 flights83.6%
- 11am–2pm511 flights73.3%
- 2pm–5pm612 flights78.4%
- 5pm–8pm516 flights76.1%
- 8pm–5am360 flights74.2%
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 73.3% on time against 91.0% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8am–11am window is the busiest, with 613 flights scheduled in it.
Across the year
Alaska on SEA to PHX through the year
July is the worst month at 60.6% 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 84.1% on time and Sunday the weakest at 75.5%. 9 points is a smaller lever than departure hour, but it is free.
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.
- 39%Carrier
- 35%Late-arriving aircraft
- 26%National Airspace System
- 1%Extreme weather
- 0%Security
35% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 27,000 reported delay minutes here, that single category outweighs weather by 35 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 27,184 reported delay minutes.
The largest share of delay minutes, 39%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 11,000 of the 27,000 delay minutes reported here.
Cancellations are rare at 0.65%, below the national 1.81% 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 3.6% land an hour or more behind schedule, against 8.1% 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 84.9% on time across 2,903 flights, 6 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 6 points of difference.
The sample behind these figures is 2,906 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 60.6%, a swing of 28 points. If the dates move at all, move them out of July before you think about anything else. 2,880 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 PHX86.9%
- American Airlines on SEA to PHX84.8%
- Delta Air Lines on SEA to PHX82.6%
- SkyWest Airlines on SEA to PHX80.2%
- Frontier Airlines on SEA to PHX70.4%
- Southwest Airlines on SEA to PHX69.0%
- 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.