67% of flights from Islip to Fort Lauderdale arrived on time over the past 12 months. That is worse than the typical U.S. route. 14% 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 ISP → FLL: when a flight was late, it was under 45 minutes late 51% of the time. About 1 in 9 flights landed an hour or more late, and 1 in 46 three hours or more; 1.9% were cancelled outright.
- On time or early67%
- 15–30 min late9.6%
- 30–60 min late9.6%
- 1–2 hours late6.2%
- 2–3 hours late3.1%
- 3+ hours late2.2%
- Diverted0.5%
- Cancelled1.9%
Share of all 418 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 |
|---|---|---|---|---|---|---|---|
| JetBlue | 396 | 69% | 1.8% | −5 min | 11.1% | +87 min | JetBlue |
| Frontier Airlines | 19 | — | — | — | — | — | Frontier Airlines |
| Southwest Airlines | 3 | — | — | — | — | — | Southwest Airlines |
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 ISP). Delays build through the day as late planes knock on, so early flights usually do best.
By month
Each calendar month pooled over 2023–2026. Best: April (86%). Worst: December (59%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 60 | — | — |
| Tuesday | 59 | — | — |
| Wednesday | 55 | — | — |
| Thursday | 61 | — | — |
| Friday | 58 | — | — |
| Saturday | 62 | — | — |
| Sunday | 63 | — | — |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Cancellations: weather 5 · airline 2 · air traffic/airport 1
Month by month
Not enough months with data to draw a trend.
Flight numbers on this route
Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.
| Flight | Departs | Flights | On time | Cancelled | Typical arrival | Operated by |
|---|---|---|---|---|---|---|
| B6 513 | 6:00 a.m. | 342 | 70% | 1.8% | −5 min | JetBlue |
Nearby airport alternatives
Other ways to make the same trip, using airports within 60 miles of Islip or Fort Lauderdale. EWR → PBI has been 8 points more reliable.
| Route | Flights | On time | Cancelled |
|---|---|---|---|
| ISP → FLL (this route) | 418 | 67% | 1.9% |
| EWR → PBI Newark to President Donald J. Trump | 3,395 | 75% | 2.8% |
| EWR → MIA Newark to Miami | 3,914 | 75% | 3.0% |
| JFK → MIA New York JFK to Miami | 4,526 | 74% | 3.1% |
| EWR → FLL Newark to Fort Lauderdale | 4,671 | 72% | 4.0% |
| JFK → PBI New York JFK to President Donald J. Trump | 2,050 | 71% | 4.6% |
| HPN → PBI Westchester to President Donald J. Trump | 1,574 | 70% | 3.0% |
Questions
How often are flights from ISP to FLL on time?
67% of 418 scheduled flights from Islip, NY to Fort Lauderdale, FL arrived within 15 minutes of schedule between September 2025 and August 2026. 1.9% were cancelled.
What month has the most delays from ISP to FLL?
December (59% on time). The best month is April (86%), over 2023–2026.
Related
- FLL → ISP (return)
- Long Island MacArthur (ISP) delays by hour
- Flights into Fort Lauderdale (FLL)
- JetBlue on-time record
- Frontier Airlines on-time record
- Southwest Airlines 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.