Nantucket Memorial (ACK) Delays and On-Time Departures
Nantucket, MA · ranked 261st of 333 airports for on-time departures
Data through July 2026 · Last updated October 18, 2026
77.0% of the 1,690 flights scheduled to depart Nantucket (ACK) in the last 12 months left on time, in line with the US average of 77.4%.
That ranks 261st of 333 US airports tracked on this site, with 5.3% of departures cancelled.
Among airlines at Nantucket (ACK), Republic Airways left on time most often (78.1%).
Over 24 months, Wednesday was the most reliable day (82% on time) and July the worst month (72%).
Best time of day to fly out of Nantucket (ACK)
On-time departure % by scheduled departure hour (local time), last 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 9am–10am | Limited data | 1 | |
| 10am–11am | 85.8% | 2.3% | 309 |
| 11am–12pm | 83.0% | 2.4% | 337 |
| 12pm–1pm | 81.8% | 2.7% | 518 |
| 1pm–2pm | 84.0% | 3.2% | 217 |
| 2pm–3pm | 81.6% | 6.7% | 341 |
| 3pm–4pm | 71.7% | 7.6% | 421 |
| 4pm–5pm | 69.9% | 10.8% | 465 |
| 5pm–6pm | 71.2% | 9.4% | 402 |
| 6pm–7pm | 73.0% | 6.1% | 245 |
| 7pm–8pm | Limited data | 10 | |
Airlines at ACK ranked by on-time departures
Last 12 months. Airlines with fewer than 30 departures are marked “limited data”.
| Airline | On-time departures | On-time arrivals | Cancelled | Departures |
|---|---|---|---|---|
| Republic Airways | 78.1% | 73.2% | 5.5% | 770 |
| JetBlue | 76.3% | 74.7% | 5.2% | 877 |
| Envoy Air | Limited data | 23 | ||
| SkyWest Airlines | Limited data | 20 | ||
80%+ good 70–79.9% fair <70% poor
Best day to fly out of ACK
On-time departures by day, 24 months.
Best month to fly out of ACK
On-time departures by month, 24 months.
Holiday travel at Nantucket (ACK)
On-time departures during holiday periods compared with all other days, last 24 months.
| Period | On-time departures | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Summer peak (Jun 15 - Aug 15) | 74.8% | -6.9 pts | 8.3% | 1,981 |
| All other days | 81.7% | — | 2.4% | 1,285 |
Monthly on-time departure trend at ACK
On-time departure % each month, with the 12-month US average for reference.
Routes from Nantucket (ACK)
Every route from ACK with its own page, by number of flights (last 12 months, on-time arrivals).
| To | On time | Cancelled | Flights |
|---|---|---|---|
| ACK → New York (LGA) | 76.5% | 5.8% | 412 |
| ACK → New York (JFK) | 72.3% | 9.0% | 301 |
| ACK → Boston (BOS) | 71.6% | 3.2% | 284 |
| ACK → Washington (DCA) | 72.1% | 4.2% | 283 |
| ACK → White Plains (HPN) | 78.0% | 4.7% | 234 |