Long Island MacArthur (ISP) Delays and On-Time Departures
Islip, NY · ranked 288th of 333 airports for on-time departures
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, Islip (ISP) had 4,966 scheduled departures and 75.2% of them left on time (US average 77.4%).
That ranks 288th of 333 US airports tracked on this site, with 2.1% of departures cancelled.
JetBlue was the most punctual airline here, with 76.5% of departures on time.
September has been the best month (86% on time) and Sunday the weakest day of the week (72%).
Best time of day to fly out of Islip (ISP)
On-time departure % by scheduled departure hour (local time), last 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 94.3% | 1.6% | 553 |
| 6am–7am | 93.0% | 1.5% | 1,313 |
| 7am–8am | 91.1% | 1.6% | 364 |
| 8am–9am | 83.7% | 1.6% | 306 |
| 9am–10am | 90.2% | 3.3% | 368 |
| 10am–11am | 85.4% | 1.3% | 603 |
| 11am–12pm | 84.1% | 1.2% | 841 |
| 12pm–1pm | 74.0% | 1.0% | 958 |
| 1pm–2pm | 72.0% | 0.9% | 649 |
| 2pm–3pm | 62.9% | 1.9% | 623 |
| 3pm–4pm | 58.5% | 2.2% | 724 |
| 4pm–5pm | 70.1% | 1.5% | 850 |
| 5pm–6pm | 62.6% | 2.0% | 657 |
| 6pm–7pm | 60.4% | 1.7% | 463 |
| 7pm–8pm | 60.1% | 1.8% | 286 |
| 8pm–9pm | 58.1% | 3.5% | 256 |
| 9pm–10pm | 69.2% | 1.7% | 172 |
| 10pm–11pm | Limited data | 11 | |
Airlines at ISP ranked by on-time departures
Last 12 months. Airlines with fewer than 30 departures are marked “limited data”.
| Airline | On-time departures | On-time arrivals | Cancelled | Departures |
|---|---|---|---|---|
| JetBlue | 76.5% | 72.0% | 2.2% | 1,532 |
| Southwest Airlines | 75.3% | 78.1% | 1.6% | 2,589 |
| Frontier Airlines | 72.5% | 73.7% | 3.4% | 845 |
80%+ good 70–79.9% fair <70% poor
Best day to fly out of ISP
On-time departures by day, 24 months.
Best month to fly out of ISP
On-time departures by month, 24 months.
Holiday travel at Islip (ISP)
On-time departures during holiday periods compared with all other days, last 24 months.
| Period | On-time departures | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 83.1% | +3.7 pts | 1.1% | 191 |
| Christmas & New Year (Dec 20 - Jan 3) | 54.0% | -25.4 pts | 2.7% | 512 |
| Summer peak (Jun 15 - Aug 15) | 67.8% | -11.6 pts | 1.7% | 1,764 |
| All other days | 79.4% | — | 1.6% | 7,530 |
Monthly on-time departure trend at ISP
On-time departure % each month, with the 12-month US average for reference.
Routes from Islip (ISP)
Every route from ISP with its own page, by number of flights (last 12 months, on-time arrivals).
| To | On time | Cancelled | Flights |
|---|---|---|---|
| ISP → Orlando (MCO) | 73.5% | 2.0% | 1,424 |
| ISP → Baltimore (BWI) | 84.8% | 1.5% | 1,235 |
| ISP → West Palm Beach/Palm Beach (PBI) | 72.2% | 2.1% | 1,221 |
| ISP → Tampa (TPA) | 72.4% | 3.8% | 445 |
| ISP → Fort Lauderdale (FLL) | 68.9% | 1.7% | 405 |