Best Time to Fly JFK to ACK: On-Time Stats by Hour & Airline
John F. Kennedy International → Nantucket Memorial
Data through July 2026 · Last updated October 18, 2026
301 flights were scheduled from New York (JFK) to Nantucket (ACK) in the last 12 months, and 82.0% of those that flew arrived on time, 4.4 points above the US average of 77.6%.
Republic Airways was the most punctual of the 2 airlines on the route at 86.3%, while JetBlue trailed at 79.5%.
September has been the best month (89% on time) and Sunday the weakest day of the week (74%).
7.0% of flights were cancelled, versus 1.8% nationally.
JFK to ACK 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 |
|---|---|---|---|---|
| Republic Airways | 86.3% | 76 min | 5.5% | 110 |
| JetBlue | 79.5% | 59 min | 7.8% | 191 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly JFK to ACK
On-time arrival % by scheduled departure hour (local time), 626 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 9am–10am | 77.2% | 10.6% | 113 |
| 10am–11am | 91.6% | 1.2% | 84 |
| 11am–12pm | Limited data | 1 | |
| 12pm–1pm | 85.1% | 1.3% | 75 |
| 1pm–2pm | 83.2% | 7.7% | 183 |
| 2pm–3pm | 72.6% | 7.7% | 91 |
| 3pm–4pm | 84.4% | 2.5% | 79 |
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 ACK
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Summer peak (Jun 15 - Aug 15) | 79.8% | -5.2 pts | 9.3% | 356 |
| All other days | 85.0% | — | 1.5% | 270 |
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).