Carrier route record

ASSEA→PDX

Alaska Airlines · Seattle to Portland

Flights: 1,124
Period: July 2025 to June 2026
Share of route: 24%
Carriers: 3

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Alaska Airlines.

Alaska on SEA to PDX lands a B, about a point worse than the national rate of 77.6%. About one flight in four 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 1,124 flights, with a median arrival 1 minute early.

The US average over the same twelve months is 77.6%, so there is little to separate Alaska on SEA to PDX from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

76.3%

Arrivals under 15 minutes late, of 1,109 completed flights

Avg delay

41 min

Across delayed arrivals only, not all flights

Cancelled

1.33%

National rate is 1.81%

Whole route

83.1%

Every carrier on SEA to PDX, 4,778 flights

These figures cover 1,124 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.

Carrier by carrier

Alaska against every carrier on SEA to PDX

Alaska flew 1,124 of the 4,778 flights on SEA to PDX, about 24% of it. Its 76.3% on time is 7 points worse than the route as a whole, which runs 83.1%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from SkyWest at 86.1% to Delta at 75.9%. 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.

On-time performance by carrier on SEA to PDX
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	3,343	86.1%	53 min	0.51%	A+
Alaska Airlines (this page)	1,124	76.3%	41 min	1.33%	B
Delta Air Linesthin sample	311	75.9%	66 min	0.00%	B+

Flight by flight

Alaska flight numbers on SEA to PDX

AS 49823:1571.6% · 307 flights

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 17 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–8am34 flights91.2%
8am–11am72 flights81.9%
11am–2pm324 flights75.4%
2pm–5pm68 flights74.6%
5pm–8pm47 flights78.3%
8pm–5am579 flights75.2%

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 91.2% of the time, against 74.6% for the afternoon window. That is 17 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 579 flights scheduled in it.

Across the year

Alaska on SEA to PDX through the year

Darker means more delays. Figures are on-time percentages.April best, July worst

July is the worst month at 46.7% on time, 37 points below April, the best at 83.7%. 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, Tuesday is the strongest day at 85.5% on time and Friday the weakest at 70.4%. 15 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Alaska runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 42% of the 11,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Late-arriving aircraft
42%
Carrier
36%
National Airspace System
17%
Extreme weather
4%

42% 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 11,000 reported delay minutes here, that single category outweighs weather by 11 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 10,807 reported delay minutes.

The largest share of delay minutes, 36%, 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 3,940 of the 11,000 delay minutes reported here.

Cancellations sit at 1.33% 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 4.1% 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 82.6% on time across 1,125 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 1,124 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 PDX

Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 83.7% on time and July 46.7%, a swing of 37 points. If the dates move at all, move them out of July before you think about anything else. 1,109 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures