Best Time to Fly JFK to SEA: On-Time Stats by Hour & Airline
John F. Kennedy International → Seattle/Tacoma International
Data through July 2026 · Last updated October 18, 2026
2,906 flights were scheduled from New York (JFK) to Seattle (SEA) in the last 12 months, and 70.2% of those that flew arrived on time, 7.4 points below the US average of 77.6%.
Delta Air Lines was the most punctual of the 3 airlines on the route at 72.9%, while Alaska Airlines trailed at 67.5%.
September has been the best month (85% on time) and Sunday the weakest day of the week (69%).
3.2% of flights were cancelled, versus 1.8% nationally.
JFK to SEA on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| Delta Air Lines | 72.9% | 58 min | 3.1% | 1,338 |
| JetBlue | 70.4% | 75 min | 4.2% | 166 |
| Alaska Airlines | 67.5% | 64 min | 3.2% | 1,402 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly JFK to SEA
On-time arrival % by scheduled departure hour (local time), 5,771 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | Limited data | 8 | |
| 7am–8am | 77.7% | 2.2% | 1,372 |
| 8am–9am | Limited data | 2 | |
| 9am–10am | 77.9% | 0.0% | 68 |
| 10am–11am | Limited data | 17 | |
| 11am–12pm | 83.8% | 1.1% | 1,046 |
| 1pm–2pm | 75.8% | 2.3% | 131 |
| 2pm–3pm | Limited data | 16 | |
| 3pm–4pm | 78.2% | 1.3% | 79 |
| 4pm–5pm | 72.4% | 1.9% | 1,384 |
| 5pm–6pm | 69.8% | 3.0% | 271 |
| 6pm–7pm | 55.6% | 3.3% | 767 |
| 7pm–8pm | 75.3% | 1.4% | 506 |
| 8pm–9pm | 70.0% | 3.9% | 104 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on JFK to SEA
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 86.1% | +10.2 pts | 0.0% | 101 |
| Christmas & New Year (Dec 20 - Jan 3) | 60.0% | -15.9 pts | 3.4% | 208 |
| Summer peak (Jun 15 - Aug 15) | 66.8% | -9.2 pts | 3.9% | 1,116 |
| All other days | 75.9% | — | 1.6% | 4,346 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).