Carrier route record

ASOAK→SEA

Alaska Airlines · Oakland to Seattle

Flights: 700
Period: July 2025 to June 2026
Share of route: 37%
Carriers: 3

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

Alaska on OAK to SEA lands a B, 4 points 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 roughly 55 minutes on average. That is a workable record, not a spotless one. That rests on 700 flights, with a median arrival 6 minutes early.

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

On time

81.1%

Arrivals under 15 minutes late, of 688 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

1.71%

National rate is 1.81%

Whole route

77.3%

Every carrier on OAK to SEA, 1,901 flights

These figures cover 700 flights between July 2025 and June 2026. The median arrival is 6 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 OAK to SEA

Alaska flew 700 of the 1,901 flights on OAK to SEA, about 37% of it. Its 81.1% on time is 4 points better than the route as a whole, which runs 77.3%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Alaska at 81.1% to Southwest at 74.9%. 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 OAK to SEA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Alaska Airlines (this page)	700	81.1%	53 min	1.71%	B
SkyWest Airlinesthin sample	71	78.3%	78 min	2.82%	B
Southwest Airlines	1,130	74.9%	47 min	0.27%	C+

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 25 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–8am324 flights91.8%
8am–11am57 flights80.4%
11am–2pm29 flights—
2pm–5pm201 flights66.7%
5pm–8pm89 flights78.2%
8pm–5am—

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 91.8% of the time, against 66.7% for the afternoon window. That is 25 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 324 flights scheduled in it.

Across the year

Alaska on OAK to SEA through the year

Darker means more delays. Figures are on-time percentages.February best, August worst

August is the worst month at 61.8% on time, 32 points below February, the best at 94.1%. 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. June was the busiest month here, with 81 flights.

Across the week, Saturday is the strongest day at 86.8% on time and Sunday the weakest at 73.8%. 13 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 43% of the 6,819 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
43%
Carrier
35%
National Airspace System
21%
Extreme weather
1%

43% 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 6,819 reported delay minutes here, that single category outweighs weather by 37 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 6,819 reported delay minutes.

The largest share of delay minutes, 35%, 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 2,364 of the 6,819 delay minutes reported here.

Cancellations sit at 1.71% 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 3.8% 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 672 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 75.3% on time across 700 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.

One caution: this is a thin sample. 700 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking Alaska on OAK to SEA

Put together: treat all of this as provisional. 700 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 81.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 688 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