Carrier route record
ASSEA→JFK
Alaska Airlines · Seattle to New York
- Flights
- 1,403
- Period
- July 2025 to June 2026
- Share of route
- 48%
- 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 JFK sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.6%. The late ones land roughly 55 minutes behind schedule. That rests on 1,403 flights, with a median arrival 2 minutes early.
The national on-time rate over the same period is 77.6%, so Alaska on SEA to JFK runs 6 points behind the country as a whole. Across a thousand flights that is about 60 extra late arrivals.
Key figures
On time
71.6%
Arrivals under 15 minutes late, of 1,354 completed flights
Avg delay
54 min
Across delayed arrivals only, not all flights
Cancelled
2.57%
National rate is 1.81%
Whole route
75.3%
Every carrier on SEA to JFK, 2,906 flights
These figures cover 1,403 flights between July 2025 and June 2026. Beyond the headline rate, 8.4% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Alaska against every carrier on SEA to JFK
Alaska flew 1,403 of the 2,906 flights on SEA to JFK, about 48% of it. Its 71.6% on time is 4 points worse than the route as a whole, which runs 75.3%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Delta at 79.6% to Alaska 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 1,337 | 79.6% | 70 min | 2.39% | B |
| JetBlue Airwaysthin sample | 166 | 72.0% | 78 min | 1.20% | C |
| Alaska Airlines (this page) | 1,403 | 71.6% | 54 min | 2.57% | C |
Flight by flight
Alaska flight numbers on SEA to JFK
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 37 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–8am140 flights94.9%
- 8am–11am337 flights80.7%
- 11am–2pm252 flights60.2%
- 2pm–5pm358 flights58.4%
- 5pm–8pm—
- 8pm–5am316 flights75.5%
Scale runs 50% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 94.9% of the time, against 58.4% for the afternoon window. That is 37 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 358 flights scheduled in it.
Across the year
Alaska on SEA to JFK through the year
July is the worst month at 29.6% on time, 60 points below February, the best at 89.9%. 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 124 flights.
Across the week, Friday is the strongest day at 75.0% on time and Sunday the weakest at 69.3%. 6 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. National Airspace System accounts for 55% 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.
- 55%National Airspace System
- 20%Carrier
- 18%Late-arriving aircraft
- 5%Extreme weather
- 1%Security
55% 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 11,000 minutes out of 21,000, against a national NAS share of 21%. The split is drawn from 20,680 reported delay minutes.
Cancellations run at 2.57%, against 1.81% nationally. That is about one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and stage length
What a delay here costs
8.4% 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 roughly 55 minutes, which a normal layover absorbs.
At 2,422 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 66.2% on time across 1,402 flights, 5 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 5 points of difference.
The sample behind these figures is 1,403 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 JFK
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 89.9% on time and July 29.6%, a swing of 60 points. If the dates move at all, move them out of July before you think about anything else. 1,354 completed flights over 12 months sit behind that.
Related
Where to go next
- SEA to JFK, every carrier
- Alaska on JFK to SEA, the return leg
- Delta Air Lines on SEA to JFK79.6%
- JetBlue Airways on SEA to JFK72.0%
- Alaska Airlines network-wide record
- Seattle-Tacoma International (SEA) delay statistics
- John F. Kennedy International (JFK) delay statistics
- The US routes with the most cancellations
- What a cancellation rate actually tells you (and what it hides)
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.