Islip to Fort Lauderdale

What the Data Says About ISP to FLL

The Islip to Fort Lauderdale corridor (ISP → FLL) covers roughly 1,092 miles and is served by 8 carriers, based on Bureau of Transportation Statistics reporting. Across 1,139 flights in the dataset, this route posts a 78.1% on-time rate with an average delay of 75.8 minutes when flights run late. Over the most recent 24 months of BTS data, 854 flights were recorded on this pairing — 20 cancelled (2.3%) and 3 diverted (0.4%). Those baseline metrics tell you what to expect before you book.

Having 8 carriers on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 1,139 total flights analyzed, the 78.1% on-time figure is statistically meaningful rather than a small-sample fluke. The 75.8-minute average delay applies only to flights that actually ran late, so it is not the average wait across all departures — the majority of flights on this route depart on time under the BTS definition of a delay (15+ minutes past schedule).

Looking at recent months, May 2025 posted the best performance on this corridor at 71% on-time, while Mar 2022 came in at 68% on-time — a 3-point gap between best and worst recent month. For travelers evaluating the ISP to FLL route, the combination of a 78.1% on-time rate, 75.8-minute average delay, 2.3% recent cancellation rate, and 8 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.