Route reliability record
OAK→SEA
Oakland to Seattle
- Flights
- 1,901
- Period
- July 2025 to June 2026
- Distance
- 672 mi
- Carriers
- 3
This route lands a B+, level with the national rate of 77.6%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by about 50 minutes on average. That is a workable record, not a spotless one. That rests on 1,901 OAK to SEA flights, of which Alaska Airlines flew 700 at 81.1% on time.
Best time to fly OAK to SEA: a 5am–8am departure, ideally on a Saturday. Flights in that window arrived on time 93.2% of the time and Saturday flights 87.1%, against 77.3% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
77.3%
Arrivals under 15 minutes late, of 1,884 completed flights
Avg delay
49 min
Across delayed arrivals only, not all flights
Cancelled
0.89%
National rate is 1.81%
Best carrier
Alaska
81.1% on time across 700 flights
These figures cover 1,901 flights between July 2025 and June 2026. The median arrival is 3 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
Which airline is most reliable on OAK to SEA
The choice of carrier is not cosmetic here. Alaska Airlines arrives on time 81.1% of the time; Southwest Airlines manages 74.9%. Sample sizes sit next to every figure, because a two-point gap across 1,130 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Alaska Airlines | 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+ |
Alaska leads Southwest by 6 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Best ways to make this trip
The most reliable ways to fly Oakland to Seattle
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 4 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. SJC → SEASan Jose to Seattle | SkyWest Airlines | 89.3% | 89.5% | 0.19% | 8pm–5am, Sat | OO 4041 07:15 |
| 2. SFO → SEASan Francisco to Seattle | Delta Air Lines | 82.2% | 83.6% | 1.73% | 5am–8am, Mon | DL 2721 05:55 |
| 3. SJC → SEASan Jose to Seattle | Alaska Airlines | 80.6% | 82.0% | 1.65% | 5am–8am, Wed | AS 1311 10:06 |
| 4. OAK → SEAOakland to Seattle | Alaska Airlines | 79.7% | 81.1% | 1.71% | 5am–8am, Sat | — |
| 5. SJC → SEASan Jose to Seattle | Southwest Airlines | 75.6% | 75.6% | 0.00% | 5am–8am, Wed | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 32 points, against 6 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am554 flights93.2%
- 8am–11am221 flights77.7%
- 11am–2pm300 flights77.9%
- 2pm–5pm287 flights66.8%
- 5pm–8pm318 flights69.3%
- 8pm–5am221 flights61.2%
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 61.2% on time, against 93.2% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 554 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 26 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
June is the worst month at 65.2% on time, 26 points below February, the best at 91.2%. 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. July was the busiest month here, with 233 flights.
Across the week, Saturday is the strongest day at 87.1% on time and Friday the weakest at 71.0%. 16 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 48% of the 21,000 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.
- 48%Late-arriving aircraft
- 34%Carrier
- 17%National Airspace System
- 0%Extreme weather
- 0%Security
48% 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 21,000 reported delay minutes here, that single category outweighs weather by 48 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 21,161 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 93.2% on time here.
Cancellations are rare at 0.89%, 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 actually 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 50 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 73.4% on time across 1,917 flights, 4 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 4 points of difference.
The sample behind these figures is 1,901 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.
Work out the risk of missing a connection in SEA after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 91.2% on time and June 65.2%, a swing of 26 points. If the dates move at all, move them out of June before you think about anything else. 1,884 completed flights over 12 months sit behind that.
Common questions
OAK to SEA questions
How often is OAK to SEA delayed?
Roughly one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 22.7% of the 1,901 flights in this analysis, against 22.4% nationally. Delayed flights are late by about 50 minutes on average.
Which airline is most reliable on OAK to SEA?
Alaska Airlines leads at 81.1% on time across 700 flights. Southwest Airlines is at the other end on 74.9%, a gap of 6 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on OAK to SEA?
The 5am–8am departure window is the strongest at 93.2% on time. The 8pm–5am window is the weakest at 61.2%, 32 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are June delays on OAK to SEA?
June is the weakest month at 65.2% on time, compared with 91.2% in February. Across the year that is 26 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- SEA to OAK — the return legseparate record
- Oakland International (OAK) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Alaska Airlines on OAK to SEA81.1%
- Southwest Airlines on OAK to SEA74.9%
- OAK to LAS, a related route78.1%
- LAX to SEA, a related route85.4%
- OAK to SAN, a related route66.9%
- Alaska Airlines on-time record81.1%
- SkyWest Airlines on-time record78.3%
- Southwest Airlines on-time record74.9%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. OAK to SEA and SEA to OAK are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.