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Airport · 12 months to July 2026
Long Island MacArthur: delays and on-time record
Islip, New York
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. Data through July 2026; this is a monthly history, not live airport status.
Reporting carriers scheduled 4,966 domestic departures from Long Island MacArthur (ISP), Islip, in the 12 months to July 2026: about 14 a day to 8 destinations.
73.7% of those flights left the gate less than 15 minutes late, 2.4 points below the national departure figure of 76.1%. Flights arriving at ISP were on time 73.6% of the time, 2.4 points below the national arrival figure of 76.0%.
2.1% of scheduled departures were cancelled (national: 1.8%), and the average departure delay, counting early and on-time departures as zero, was 18.8 min.
Southwest Airlines is the largest reporting carrier at ISP with 52% of departures. Among carriers with at least 120 departures, Southwest Airlines had the highest on-time arrival share for its ISP departures (76.7%) and JetBlue Airways the lowest (69.8%).
On-time departures are down 2.4 points on the previous 12 months (76.1%).
Of the delay minutes that carriers assigned to a BTS cause category for flights leaving ISP, late-arriving aircraft 43%, air carrier 27% and national aviation system 23%.
- On time 73.6%
- Arrived 15+ minutes late 23.9%
- Cancelled 2.1%
- Diverted 0.4%
As origin and as destination, against the nation
| Measure | Departures from ISP | Arrivals at ISP | All reported flights | ISP departures, previous 12 months |
|---|---|---|---|---|
| Departed on time (less than 15 min late) | 73.7% | 71.9% | 76.1% | 76.1% |
| Arrived on time | 73.6% | 73.6% | 76.0% | 76.5% |
| Cancelled | 2.1% | 1.9% | 1.8% | 1.3% |
| Diverted | 0.4% | 0.3% | 0.3% | 0.3% |
| Average departure delay (late minutes only) | 18.8 min | 17.0 min | 17.4 min | 19.4 min |
| Arrival delay minutes per 100 flights | 1,798 | 1,548 | 1,684 | 1,851 |
| Scheduled flights | 4,966 | 4,966 | 7,043,858 | 5,031 |
12 months to July 2026. The first column follows flights that left ISP; the second follows flights that landed there. Year on year, on-time departures moved −2.4 pts.
Airlines at ISP
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| WN Southwest Airlines | 2,589 | 52% | 76.7% | 7.2 min | 1.6% |
| B6 JetBlue Airways | 1,532 | 31% | 69.8% | 15.1 min | 2.2% |
| F9 Frontier Airlines | 845 | 17% | 70.9% | 10.2 min | 3.4% |
Departures from ISP by reporting carrier, ordered by flights; on time means the flight reached its destination less than 15 minutes late. Green is at or above the airport's overall share of 73.6%. Carriers fly different routes at different hours, so the rows are not a like-for-like test.
Busiest routes from ISP
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| ISP–MCO | Islip to Orlando | 1,424 | 71.5% | 11.7 min | 2.0% |
| ISP–BWI | Islip to Baltimore | 1,235 | 83.2% | 2.9 min | 1.5% |
| ISP–PBI | Islip to West Palm Beach/Palm Beach | 1,221 | 70.4% | 13.6 min | 2.1% |
| ISP–TPA | Islip to Tampa | 445 | 69.7% | 10.3 min | 3.8% |
| ISP–FLL | Islip to Fort Lauderdale | 405 | 67.4% | 17.3 min | 1.7% |
| ISP–MYR | Islip to Myrtle Beach | 121 | 81.0% | -0.2 min | 3.3% |
| ISP–RSW | Islip to Fort Myers | 111 | 60.4% | 14.5 min | 2.7% |
| ISP–MIA | Islip to Miami | 4 | 50.0% | 33.5 min | 0.0% |
Routes with at least 10 flights a month have their own page.
Month by month
By scheduled departure hour
Among hours with at least 99 departures, 6 am to 7 am had the highest on-time share (92.4% of 661 flights) and 2 pm to 3 pm the lowest (56.3% of 277).
Delay causes
Cancellations by reported reason (104 in the period): air carrier 19%, weather 66%, national aviation system 14%, security 0%.
Checkpoint volumes
TSA publishes daily checkpoint passenger counts for the country as a whole, not for ISP on its own. The national series through September 2026 is on the checkpoint volumes page.
Questions and answers
How often do flights leave ISP on time?
73.7% of the 4,966 scheduled domestic departures in the 12 months to July 2026 left less than 15 minutes late; the national figure was 76.1%. 2.1% were cancelled.
How often do flights arrive at ISP on time?
73.6% of 4,966 scheduled arrivals were on time by the BTS definition, against 76.0% nationally.
Which airline has the highest on-time share at ISP?
Counting departures from ISP and whether they reached their destination on time, Southwest Airlines had the highest share (76.7% of 2,589 flights), then Frontier Airlines (70.9%) and JetBlue Airways (69.8%). Carriers fly different routes at different hours, so the figures are not a like-for-like test.
What causes delays at ISP?
For departures from ISP that reached their destination 15 or more minutes late, carriers attributed the delay minutes as follows: late-arriving aircraft 43%, air carrier 27%, national aviation system 23%, extreme weather 7%, security 0%.
What time of day has the highest on-time share at ISP?
Departures scheduled from 6 am to 7 am local time left on time 92.4% of the time, the highest of any hour with enough flights to compare; 2 pm to 3 pm was lowest at 56.3%.
Is it getting better?
On-time departures for the 12 months to July 2026 were 73.7%, down 2.4 points on the previous 12 months (76.1%). The monthly chart shows each of the last 36 months, and each month has its own page.
Does this page show today's delays at ISP?
No. BTS publishes on-time records about two months after the month ends, so this page is a monthly history through July 2026. For live conditions use the FAA airport status service or your airline.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance (1987 to present), monthly files August 2023 to July 2026; airport name from the BTS airport lookup table. US government works in the public domain. Domestic scheduled flights by reporting carriers only: international flights, charters and smaller carriers are not in the source. Totals and averages only; no individual flight or aircraft is identified. See the methodology; report processing errors through corrections.