67% of flights from New York to Seattle arrived on time over the past 12 months. That is worse than the typical U.S. route. The 11 a.m. departures ran on time 78% of the time; the 6 p.m. ones 51%. Most reliable airline: Delta Air Lines (69%). 13% of flights arrived more than an hour late or not at all.
How late?
The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for JFK → SEA: when a flight was late, it was under 45 minutes late 59% of the time. About 1 in 11 flights landed an hour or more late, and 1 in 45 three hours or more; 3.4% were cancelled outright.
- On time or early67%
- 15–30 min late12%
- 30–60 min late8.6%
- 1–2 hours late5.3%
- 2–3 hours late1.7%
- 3+ hours late2.2%
- Diverted0.3%
- Cancelled3.4%
Share of all 2,906 scheduled flights, past 12 months, by arrival time against schedule.
By airline
| Airline | Flights | On time | Cancelled | Typical arrival | 1h+ late | Avg when late | Operated by |
|---|---|---|---|---|---|---|---|
| Alaska Airlines | 1,401 | 66% | 3.4% | 0 min | 9.9% | +65 min | Alaska Airlines |
| Delta Air Lines | 1,339 | 69% | 3.2% | −2 min | 7.2% | +60 min | Delta Air Lines |
| JetBlue | 166 | 61% | 6.0% | +3 min | 19.3% | +94 min | JetBlue |
Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.
Best time of day to fly
On-time rate by scheduled departure hour (local time at JFK). Delays build through the day as late planes knock on, so early flights usually do best.
By airline and hour
| Departs | Alaska Airlines | Delta Air Lines | JetBlue |
|---|---|---|---|
| 7 a.m. | 68% | 71% | — |
| 11 a.m. | 74% | 83% | — |
| 4 p.m. | 67% | 67% | — |
| 5 p.m. | — | — | 50% |
| 6 p.m. | 46% | 51% | — |
| 7 p.m. | — | 70% | — |
| 8 p.m. | 60% | — | — |
Last flight of the day
On JFK → SEA, each airline's last flight of the day was cancelled 3.3% of the time, against 3.3% for its earlier flights, about the same. It arrived 3+ hours late 2.5% of the time (earlier flights: 1.9%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.
| Airline | Last departure | Last: cancelled | Last: 3h+ late | Earlier: cancelled | Next morning |
|---|---|---|---|---|---|
| Alaska Airlines | 8:23 p.m. | 2.8% | 4.1% | 3.6% | first flight 7:00 a.m. |
| Delta Air Lines | 7:30 p.m. | 3.8% | 0.8% | 3.0% | first flight 7:00 a.m. |
Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.
By month
Each calendar month pooled over 2023–2026. Best: September (83%). Worst: June (63%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 427 | 66% | 3.5% |
| Tuesday | 410 | 68% | 3.4% |
| Wednesday | 412 | 72% | 1.2% |
| Thursday | 412 | 65% | 3.6% |
| Friday | 417 | 69% | 2.4% |
| Saturday | 410 | 69% | 5.1% |
| Sunday | 418 | 61% | 4.8% |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Cancellations: weather 57 · airline 26 · air traffic/airport 17
Month by month
Flight numbers on this route
Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.
| Flight | Departs | Flights | On time | Cancelled | Typical arrival | Operated by |
|---|---|---|---|---|---|---|
| AS 21 | 7:00 a.m. | 358 | 66% | 3.6% | 0 min | Alaska Airlines |
| DL 699 | 7:00 a.m. | 365 | 71% | 3.0% | −3 min | Delta Air Lines |
| AS 23 | 11:30 a.m. | 356 | 76% | 2.5% | −6 min | Alaska Airlines |
| DL 1719 | 11:30 a.m. | 141 | 77% | 2.8% | −1 min | Delta Air Lines |
| AS 31 | 4:29 p.m. | 363 | 68% | 4.7% | −3 min | Alaska Airlines |
| DL 740 | 4:40 p.m. | 365 | 66% | 3.3% | −1 min | Delta Air Lines |
| B6 263 | 5:29 p.m. | 166 | 61% | 6.0% | +3 min | JetBlue |
| DL 688 | 6:59 p.m. | 359 | 62% | 3.9% | +3 min | Delta Air Lines |
| AS 17 | 8:23 p.m. | 287 | 49% | 1.7% | +13 min | Alaska Airlines |
Worst days in the past year
| Date | Flights | On time | Cancelled |
|---|---|---|---|
| Jul 19, 2026 | 9 | 0% | 2 |
| Jul 21, 2026 | 9 | 0% | 4 |
| Nov 14, 2025 | 8 | 0% | 1 |
| Dec 14, 2025 | 8 | 0% | 4 |
| Dec 15, 2025 | 8 | 0% | 1 |
Nearby airport alternatives
Other ways to make the same trip, using airports within 60 miles of New York or Seattle. EWR → SEA has been 4 points more reliable.
| Route | Flights | On time | Cancelled |
|---|---|---|---|
| JFK → SEA (this route) | 2,906 | 67% | 3.4% |
| EWR → SEA Newark to Seattle-Tacoma | 2,263 | 71% | 2.4% |
Questions
How often are flights from JFK to SEA on time?
67% of 2,906 scheduled flights from New York, NY to Seattle, WA arrived within 15 minutes of schedule between September 2025 and August 2026. 3.4% were cancelled.
What is the best time of day to fly JFK to SEA?
Flights scheduled to leave at 11 a.m. were the most reliable (78% on time). The 6 p.m. departures were the least (51%).
Which airline is most on time from JFK to SEA?
Delta Air Lines: 69% of its 1,339 flights on the route arrived on time. Alaska Airlines: 66%. JetBlue: 61%.
What month has the most delays from JFK to SEA?
June (63% on time). The best month is September (83%), over 2023–2026.
Is the last flight of the day from JFK to SEA more likely to be cancelled?
Not much. Each airline's last JFK–SEA flight of the day was cancelled 3.3% of the time over the past year, against 3.3% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.
Related
- SEA → JFK (return)
- New York JFK (JFK) delays by hour
- Flights into Seattle-Tacoma (SEA)
- Alaska Airlines on-time record
- Delta Air Lines on-time record
- JetBlue on-time record
- Connecting off this flight? Check the risk
Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.