Carrier route record
ASPDX→SEA
Alaska Airlines · Portland to Seattle
- Flights
- 1,125
- Period
- July 2025 to June 2026
- Share of route
- 23%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on PDX to SEA lands a B, 5 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by roughly 40 minutes on average. That is a workable record, not a spotless one. That rests on 1,125 flights, with a median arrival 2 minutes early.
Set against the rest of the country, Alaska's PDX to SEA record is 5 points better than the US average of 77.6%. That gap is worth roughly 50 fewer late arrivals for every thousand flights.
Key figures
On time
82.6%
Arrivals under 15 minutes late, of 1,112 completed flights
Avg delay
42 min
Across delayed arrivals only, not all flights
Cancelled
1.16%
National rate is 1.81%
Whole route
84.8%
Every carrier on PDX to SEA, 4,938 flights
These figures cover 1,125 flights between July 2025 and June 2026. The median arrival is 2 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 PDX to SEA
Alaska flew 1,125 of the 4,938 flights on PDX to SEA, about 23% of it. Its 82.6% on time is 2 points worse than the route as a whole, which runs 84.8%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Delta at 87.8% to Alaska at 82.6%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Linesthin sample | 312 | 87.8% | 61 min | 0.00% | A+ |
| SkyWest Airlines | 3,501 | 85.2% | 59 min | 0.54% | A+ |
| Alaska Airlines (this page) | 1,125 | 82.6% | 42 min | 1.16% | B |
Flight by flight
Alaska flight numbers on PDX to SEA
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 14 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am514 flights88.0%
- 8am–11am164 flights74.1%
- 11am–2pm266 flights77.4%
- 2pm–5pm58 flights86.2%
- 5pm–8pm121 flights81.0%
- 8pm–5am2 flights—
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 88.0% of the time, against 74.1% for the morning window. That is 14 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 514 flights scheduled in it.
Across the year
Alaska on PDX to SEA through the year
June is the worst month at 72.8% on time, 23 points below April, the best at 95.5%. 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 125 flights.
Across the week, Sunday is the strongest day at 87.0% on time and Friday the weakest at 74.5%. 13 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 8,020 reported delay minutes.
- 33%Carrier
- 33%Late-arriving aircraft
- 32%National Airspace System
- 2%Extreme weather
32% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 2,567 minutes out of 8,020, against a national NAS share of 21%. The split is drawn from 8,020 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 88.0% on time here.
Cancellations sit at 1.16% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 3.0% 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.
At 129 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 76.3% on time across 1,124 flights, 6 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 6 points of difference.
The sample behind these figures is 1,125 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 PDX to SEA
Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 95.5% on time and June 72.8%, a swing of 23 points. If the dates move at all, move them out of June before you think about anything else. 1,112 completed flights over 12 months sit behind that.
Related
Where to go next
- PDX to SEA, every carrier
- Alaska on SEA to PDX, the return leg
- Delta Air Lines on PDX to SEA87.8%
- SkyWest Airlines on PDX to SEA85.2%
- Alaska Airlines network-wide record
- Portland International (PDX) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.