OnTimeStats

Airport on-time performance

ISP

Islip

Data through Dec 2025Source: US DOT · BTS
On-time rate75%flights departing here that arrived on time
Median delayon timetypical departure delay
p90 delay50 min1 in 10 departures is worsetail risk
Cancelled1.0%of scheduled departures
Left the gate on time77%departures that pushed back within 15 min of schedule (DepDel15)

based on 5,283 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

As a connection hub

Arriving here (inbound performance)

These figures reflect inbound flights arriving at this airport — relevant for connections and layovers.

75%arrived on time here
(within 15 min, inbound flights)
  • On time75%
  • 15–59 min late15%
  • 1–2 hr late5%
  • 2 hr+ late3%
  • Cancelled or diverted1%

Arrival outcomes for inbound flights. Last segment = cancelled or diverted.

Bad day: 1 in 10 flights arrives more than 50 min late.

By airline

Carriers departing here (last 12 months)

Delay = arrival delay (ArrDel15-based)

  • Southwest Airlinesbest
    On-time79%
    Medianon time
    p9040 min
    Cancel0.6%
    Flights2,825
  • Frontier Airlines
    On-time71%
    Medianon time
    p9075 min
    Cancel1.7%
    Flights642
  • JetBlue Airways
    On-time69%
    Medianon time
    p9065 min
    Cancel0.2%
    Flights828

Over time

Departure on-time trend

By season

On-time rate by month

Where flights go

Busiest routes

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Methodology

A flight is on time when it arrives within 15 minutes of schedule — the US DOT / BTS standard. Median and p90(the “1-in-10 bad day”) are read from the full arrival-delay distribution, never averaged across periods.

Figures cover a carrier’s own BTS-coded flights. Cells below ~200 flights are flagged as limited data. All numbers are pre-computed from public BTS On-Time Performance data.