Long Island MacArthur in September 2025

85.8%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 September 2025, reporting carriers scheduled 351 domestic departures from Long Island MacArthur (ISP). 85.8% left less than 15 minutes late and 82.6% reached their destination on time; 0.3% were cancelled.

Nationally that month, 83.1% of flights departed on time and 82.8% arrived on time, so ISP departures were 2.7 points above the national departure figure.

A year earlier, in September 2024, the airport had 292 departures with 84.9% leaving on time: a change of +0.9 points, with flights up 20%.

Flights arriving at ISP that month were on time 87.4% of the time (350 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, national aviation system 42%, air carrier 30% and late-arriving aircraft 28%.

On time 82.6%
Arrived 15+ minutes late 16.5%
Cancelled 0.3%
Diverted 0.6%

Every scheduled departure from ISP in September 2025, judged by arrival at the destination.

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

Measure	Sep 2025	Sep 2024	ISP, 12 months to Jul 2026	All reported flights, Sep 2025
Departed on time	85.8%	84.9%	73.7%	83.1%
Arrived on time	82.6%	88.0%	73.6%	82.8%
Cancelled	0.3%	1.0%	2.1%	0.5%
Average departure delay (late minutes only)	9.0 min	10.1 min	18.8 min	12.2 min
Scheduled departures a day	12	10	14	18,748
Scheduled departures	351	292	4,966	562,439

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
WN Southwest Airlines	201	57%	85.6%	4.2 min	0.0%
B6 JetBlue Airways	78	22%	73.1%	5.1 min	0.0%
F9 Frontier Airlines	72	21%	84.7%	-3.7 min	1.4%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
ISP–MCO	Islip to Orlando	108	80.6%	1.6 min	0.0%
ISP–BWI	Islip to Baltimore	90	95.6%	-2.0 min	0.0%
ISP–PBI	Islip to West Palm Beach/Palm Beach	86	75.6%	8.7 min	0.0%
ISP–TPA	Islip to Tampa	36	75.0%	11.4 min	2.8%
ISP–FLL	Islip to Fort Lauderdale	18	66.7%	4.5 min	0.0%
ISP–MYR	Islip to Myrtle Beach	13	100.0%	-19.3 min	0.0%

By scheduled departure hour

100

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

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

Delay causes

BTS cause category	Share of delay minutes	National, Sep 2025	Minutes
Air carrier	29.6%	34.3%	970
Late-arriving aircraft	28.1%	37.4%	920
National Aviation System	42.2%	22.6%	1,382
Extreme weather	0.0%	5.6%	0
Security	0.0%	0.1%	0

3,272 delay minutes on 58 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 ISP on time in September 2025?

85.8% of 351 scheduled domestic departures left less than 15 minutes late, and 82.6% reached their destination on time. The national figures that month were 83.1% and 82.8%.

How does that compare with a year earlier?

In September 2024, 84.9% of 292 departures left on time and 1.0% were cancelled, against 85.8% and 0.3% in September 2025.

Provenance

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