Carrier route record

ASSEA→OAK

Alaska Airlines · Seattle to Oakland

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 SEA to OAK sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land about 45 minutes behind schedule. 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 SEA to OAK from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

75.3%

Arrivals under 15 minutes late, of 689 completed flights

Avg delay

45 min

Across delayed arrivals only, not all flights

Cancelled

1.57%

National rate is 1.81%

Whole route

73.4%

Every carrier on SEA to OAK, 1,917 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 SEA to OAK

Alaska flew 700 of the 1,917 flights on SEA to OAK, about 37% of it. Its 75.3% on time is 2 points better than the route as a whole, which runs 73.4%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from SkyWest at 81.8% to Southwest at 71.6%. 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.

On-time performance by carrier on SEA to OAK
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlinesthin sample	90	81.8%	51 min	2.22%	B
Alaska Airlines (this page)	700	75.3%	45 min	1.57%	B
Southwest Airlines	1,127	71.6%	54 min	0.09%	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 21 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–8am21 flights—
8am–11am28 flights—
11am–2pm219 flights69.0%
2pm–5pm106 flights89.5%
5pm–8pm41 flights75.6%
8pm–5am285 flights74.5%

Scale runs 60% 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 69.0% on time against 89.5% for 2pm–5pm. 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 8pm–5am window is the busiest, with 285 flights scheduled in it.

Across the year

Alaska on SEA to OAK through the year

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

August is the worst month at 54.5% on time, 38 points below February, the best at 92.2%. 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, Tuesday is the strongest day at 80.4% on time and Thursday the weakest at 70.2%. 10 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 50% of the 7,601 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
50%
Carrier
38%
National Airspace System
11%
Extreme weather
1%
Security
1%

50% 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 7,601 reported delay minutes here, that single category outweighs weather by 49 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 7,601 reported delay minutes.

The largest share of delay minutes, 38%, 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 2,856 of the 7,601 delay minutes reported here.

Cancellations sit at 1.57% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

5.1% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 45 minutes, which a normal layover absorbs.

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 81.1% on time across 700 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.

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 SEA to OAK

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 75.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 689 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