67% of flights from Nantucket to New York arrived on time over the past 12 months. That is worse than the typical U.S. route. The noon departures ran on time 68% of the time; the 4 p.m. ones 63%. 21% 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 ACK → LGA: when a flight was late, it was under 45 minutes late 34% of the time. About 1 in 8 flights landed an hour or more late, and 1 in 37 three hours or more; 8.5% were cancelled outright.
- On time or early67%
- 15–30 min late5.1%
- 30–60 min late6.8%
- 1–2 hours late8.3%
- 2–3 hours late1.7%
- 3+ hours late2.7%
- Diverted0.2%
- Cancelled8.5%
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 | 66% | 8.6% | −4 min | 11.8% | +78 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 ACK). Delays build through the day as late planes knock on, so early flights usually do best.
By airline and hour
| Departs | Delta Air Lines |
|---|---|
| noon | 68% |
| 4 p.m. | 63% |
Last flight of the day
On ACK → LGA, each airline's last flight of the day was cancelled 14.3% of the time, against 3.2% for its earlier flights (4.5× as often). It arrived 3+ hours late 1.6% of the time (earlier flights: 3.2%). 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 | 4:40 p.m. | 15.4% | 1.8% | 1.8% | first flight 12:13 p.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 LGA 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 (77%). Worst: July (65%).
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: airline 13 · air traffic/airport 13 · weather 9
Month by month
Worst days in the past year
| Date | Flights | On time | Cancelled |
|---|---|---|---|
| Aug 27, 2026 | 4 | 0% | 2 |
| Jul 9, 2026 | 4 | 0% | 0 |
| Aug 10, 2026 | 4 | 0% | 1 |
| Jul 18, 2026 | 4 | 0% | 2 |
| Jun 12, 2026 | 4 | 0% | 1 |
Questions
How often are flights from ACK to LGA on time?
67% of 411 scheduled flights from Nantucket, MA to New York, NY arrived within 15 minutes of schedule between September 2025 and August 2026. 8.5% were cancelled.
What is the best time of day to fly ACK to LGA?
Flights scheduled to leave at noon were the most reliable (68% on time). The 4 p.m. departures were the least (63%).
What month has the most delays from ACK to LGA?
July (65% on time). The best month is August (77%), over 2023–2026.
Is the last flight of the day from ACK to LGA more likely to be cancelled?
Yes. Each airline's last ACK–LGA flight of the day was cancelled 14.3% of the time over the past year, against 3.2% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.
Related
- LGA → ACK (return)
- Nantucket Memorial (ACK) delays by hour
- Flights into LaGuardia (LGA)
- 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.