75% of flights from New York to Nantucket arrived on time over the past 12 months. That is worse than the typical U.S. route. The 10 a.m. departures ran on time 80% of the time; the 2 p.m. ones 73%. 12% 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 LGA → ACK: when a flight was late, it was under 45 minutes late 49% of the time. About 1 in 15 flights landed an hour or more late, and 1 in 206 three hours or more; 4.9% were cancelled outright.
- On time or early75%
- 15–30 min late6.1%
- 30–60 min late6.3%
- 1–2 hours late5.6%
- 2–3 hours late0.7%
- 3+ hours late0.5%
- Diverted0.7%
- Cancelled4.9%
Share of all 411 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 |
|---|---|---|---|---|---|---|---|
| Delta Air Lines | 220 | 77% | 3.2% | −11 min | 6.8% | +59 min | Republic Airways |
| American Airlines | 99 | — | — | — | — | — | Republic Airways |
| JetBlue | 92 | — | — | — | — | — | 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 LGA). Delays build through the day as late planes knock on, so early flights usually do best.
By airline and hour
| Departs | Delta Air Lines |
|---|---|
| 10 a.m. | 80% |
| 2 p.m. | 73% |
Last flight of the day
On LGA → ACK, each airline's last flight of the day was cancelled 5.6% of the time, against 1.6% for its earlier flights (3.5× as often). It arrived 3+ hours late 1.6% of the time (earlier flights: 0.0%). 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 |
|---|---|---|---|---|---|
| Delta Air Lines | 2:20 p.m. | 5.5% | 1.8% | 0.9% | first flight 10:10 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.
If you need to be in ACK tonight, book an earlier flight so there's a backup if it's cancelled.
By month
Each calendar month pooled over 2023–2026. Best: August (84%). Worst: July (72%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 62 | — | — |
| Tuesday | 48 | — | — |
| Wednesday | 46 | — | — |
| Thursday | 59 | — | — |
| Friday | 68 | — | — |
| Saturday | 60 | — | — |
| Sunday | 68 | — | — |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Cancellations: air traffic/airport 8 · airline 7 · weather 5
Month by month
Worst days in the past year
| Date | Flights | On time | Cancelled |
|---|---|---|---|
| Jul 18, 2026 | 4 | 0% | 3 |
| Aug 27, 2026 | 4 | 0% | 1 |
| Jul 21, 2026 | 3 | 0% | 2 |
| Jul 28, 2026 | 3 | 0% | 2 |
| Jul 19, 2026 | 5 | 20% | 2 |
Questions
How often are flights from LGA to ACK on time?
75% of 411 scheduled flights from New York, NY to Nantucket, MA arrived within 15 minutes of schedule between September 2025 and August 2026. 4.9% were cancelled.
What is the best time of day to fly LGA to ACK?
Flights scheduled to leave at 10 a.m. were the most reliable (80% on time). The 2 p.m. departures were the least (73%).
What month has the most delays from LGA to ACK?
July (72% on time). The best month is August (84%), over 2023–2026.
Is the last flight of the day from LGA to ACK more likely to be cancelled?
Yes. Each airline's last LGA–ACK flight of the day was cancelled 5.6% of the time over the past year, against 1.6% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.
Related
- ACK → LGA (return)
- LaGuardia (LGA) delays by hour
- Flights into Nantucket Memorial (ACK)
- Delta Air Lines on-time record
- American Airlines 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.