Nantucket Memorial in August 2025

84.0%departed on time

BTS: A flight is counted as on time if it arrived less than 15 minutes after its scheduled time. Only carriers with at least 0.5 percent of domestic scheduled passenger revenue report.

In August 2025, reporting carriers scheduled 481 domestic departures from Nantucket Memorial (ACK). 84.0% left less than 15 minutes late and 80.7% reached their destination on time; 1.2% were cancelled.

Nationally that month, 76.8% of flights departed on time and 76.3% arrived on time, so ACK departures were 7.2 points above the national departure figure.

A year earlier, in August 2024, the airport had 474 departures with 74.1% leaving on time: a change of +9.9 points, with flights up 1%.

Flights arriving at ACK that month were on time 88.4% of the time (481 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, national aviation system 42%, late-arriving aircraft 39% and air carrier 19%.

On time 80.7%
Arrived 15+ minutes late 18.1%
Cancelled 1.2%
Diverted 0.0%

Every scheduled departure from ACK in August 2025, judged by arrival at the destination.

August 2025 against a year earlier, the airport's year and the nation

Measure	Aug 2025	Aug 2024	ACK, 12 months to Jul 2026	All reported flights, Aug 2025
Departed on time	84.0%	74.1%	73.0%	76.8%
Arrived on time	80.7%	69.6%	69.6%	76.3%
Cancelled	1.2%	8.9%	5.3%	1.1%
Average departure delay (late minutes only)	9.7 min	23.2 min	20.9 min	17.6 min
Scheduled departures a day	16	16	5	20,079
Scheduled departures	481	474	1,690	602,378

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
B6 JetBlue Airways	240	50%	87.9%	-4.3 min	0.4%
YX Republic Airline	230	48%	75.2%	7.9 min	1.7%
OO SkyWest Airlines	6	1%	33.3%	26.6 min	16.7%
MQ Envoy Air	5	1%	40.0%	38.2 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
ACK–LGA	Nantucket to New York	126	87.3%	-1.5 min	0.8%
ACK–DCA	Nantucket to Washington	98	81.6%	-1.2 min	1.0%
ACK–JFK	Nantucket to New York	85	77.6%	6.4 min	1.2%
ACK–BOS	Nantucket to Boston	62	85.5%	-6.0 min	0.0%
ACK–HPN	Nantucket to White Plains	62	90.3%	-6.1 min	1.6%
ACK–PHL	Nantucket to Philadelphia	32	46.9%	32.3 min	3.1%
ACK–ORD	Nantucket to Chicago	11	54.5%	40.2 min	9.1%
ACK–CLT	Nantucket to Charlotte	5	40.0%	38.2 min	0.0%

By scheduled departure hour

On-time share:under 62%6270768288% and over

Share of departures that left less than 15 minutes late, by scheduled hour (local time), August 2025.

Delay causes

BTS cause category	Share of delay minutes	National, Aug 2025	Minutes
Air carrier	18.8%	33.1%	973
Late-arriving aircraft	38.7%	40.5%	2,000
National Aviation System	42.1%	19.2%	2,176
Extreme weather	0.4%	7.0%	20
Security	0.0%	0.1%	0

5,169 delay minutes on 87 flights that arrived 15 or more minutes late and carried a cause report. Carriers assign the categories; see what each category means.

Questions and answers

How many flights left ACK on time in August 2025?

84.0% of 481 scheduled domestic departures left less than 15 minutes late, and 80.7% reached their destination on time. The national figures that month were 76.8% and 76.3%.

How does that compare with a year earlier?

In August 2024, 74.1% of 474 departures left on time and 8.9% were cancelled, against 84.0% and 1.2% in August 2025.

Provenance

Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for August 2025; public domain. Domestic scheduled flights by reporting carriers, totals and averages only. The site's data runs through July 2026. Full record for ACK · methodology · corrections.