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Airport · ISP · Islip, New York

Islip, NY

According to PlainFlights' airport traffic ranking (BTS On-Time Performance total flights), Islip, NY (ISP) ranks #142 of 382 tracked US airports by total flights (most flights = #1). Islip, NY posts bottom-quartile on-time performance among the 382 tracked U.S. airports, as a mid-size U.S. airport.

Data updated 2026-06-13

77.9%
On-time
Top 92%
on-time, US airports
71 min
Delay when late
1.62%
Cancelled
#142 of 382
Corpus placement
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ISP on-time rate vs. the national average

Behind the U.S. average across all 382 tracked airports.

0%100%U.S. average79%77.9%

Delay Cause Breakdown

Top delay cause: Late Aircraft. Total delay minutes: 400,850.

Late Aircraft 45.0% (180,201 min)
Carrier 26.4% (105,784 min)
NAS (National Aviation System) 25.5% (102,342 min)
Weather 3.0% (12,197 min)
Security 0.1% (326 min)

ISP - seasonal on-time pattern

Best: November (92%) · worst: July (85.3%)

84%86%88%90%92%94% JanFebMarAprMayJunJulAugSepOctNovDec 87%

ISP - on-time rate by year

2020–2025, year-over-year trend.

85%90%95%100% 202020212022202320242025 96.8% 88.4% ▼ -8.7%

ISP - taxi-out and taxi-in (monthly)

Average taxi-out 12.4 min · taxi-in 4.9 min over the last 24 reported months (U.S. airport mean taxi-out ≈ 16.4 min).

10 min12 min14 min16 min Jan 24Dec 25 14 min 15.4 min ▲ +10.0%

ISP's average taxi-out (12.4 min) stays shorter than the recent U.S. airport mean (~16.4 min). Even the heaviest month (December 2025, 15.4 min) is milder than many hubs' typical book.

Cancellation & Diversion Analysis

Flight disruption statistics for Islip, NY.

Cancellation Rate

1.62%

881 of 54,300 flights

Diversion Rate

0.14%

75 of 54,300 flights

Delay Rate

22.1%

11,984 of 54,300 flights

Top Routes from ISP

Busiest routes to and from Islip, NY.

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Route Flights On-Time Distance
ISP (Islip) → MCO (Orlando) 7,628 77.6% 971 mi
MCO (Orlando) → ISP (Islip) 7,608 75.7% 971 mi
BWI (Baltimore) → ISP (Islip) 7,398 76.7% 220 mi
ISP (Islip) → BWI (Baltimore) 7,390 88.3% 220 mi
ISP (Islip) → PBI (West Palm Beach/Palm Beach) 4,604 76.2% 1,052 mi
PBI (West Palm Beach/Palm Beach) → ISP (Islip) 4,599 76.2% 1,052 mi
TPA (Tampa) → ISP (Islip) 2,419 81.1% 1,034 mi
ISP (Islip) → TPA (Tampa) 2,416 73% 1,034 mi
FLL (Fort Lauderdale) → ISP (Islip) 1,202 74.4% 1,092 mi
ISP (Islip) → FLL (Fort Lauderdale) 1,139 78.1% 1,092 mi

Nationwide peers by on-time rate & flight volume

Two PlainFlights-derived comparison paths for Islip, NY, both outside New York so the neighborhoods are not same-state geography. Axes stay disjoint: volume peers exclude the on-time peer set. Same-state compare stays below.

Similar on-time rate

Nearest out-of-state BTS on-time rate (this airport: 77.9%).

Miami, FL

Miami, FL

77.9% on-time 1,160,127 flights

Las Vegas, NV

Las Vegas, NV

78% on-time 1,986,833 flights

Baltimore, MD

Baltimore, MD

78% on-time 1,049,006 flights

Eagle, CO

Eagle, CO

78% on-time 37,271 flights

Similar flight volume

Nearest out-of-state total flights (this airport: 54,300).

Baton Rouge, LA

Baton Rouge, LA

53,837 flights 84.2% on-time

Shreveport, LA

Shreveport, LA

55,112 flights 83.1% on-time

Missoula, MT

Missoula, MT

52,758 flights 83.9% on-time

Juneau, AK

Juneau, AK

52,533 flights 85.3% on-time

Other Airports in New York

Compare performance with other New York airports.

LGA 81.2%

New York, NY

New York · 1,574,867 flights
JFK 79.4%

New York, NY

New York · 1,274,816 flights
BUF 80.6%

Buffalo, NY

Buffalo · 221,909 flights
SYR 81.5%

Syracuse, NY

Syracuse · 131,663 flights
ALB 80.9%

Albany, NY

Albany · 129,222 flights
ROC 82%

Rochester, NY

Rochester · 126,934 flights
HPN 79.1%

White Plains, NY

White Plains · 117,692 flights
ELM 84.5%

Elmira/Corning, NY

Elmira/Corning · 13,181 flights

ISP delay-share reading

The standout signal at Islip, NY is the delay mix: Late Aircraft owns 45.0% of 400,850 delay minutes across 54,300 BTS flights. The on-time headline is 77.9% (1.1 pts below the 79% national average), with 11,984 delayed and 881 cancelled (1.62%).

Delay minutes concentrate in Late Aircraft (45.0% late-aircraft, 26.4% carrier, 25.5% NAS, 3.0% weather, 0.1% security). Mid-volume books still show a clear delay fingerprint rather than a weather-only story.

On the multi-year calendar, ISP is strongest in November (92% on-time) and weakest in July (85.3%), a 6.7-point swing. Volume peaks in March (~891 flights/month). The busiest connecting route is to MCO (Orlando) at 77.6% on-time. Field definitions: on-time performance explained.

Statewide aggregates for New York: New York flight data.

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data (2020–2025). Statistics reflect cumulative performance across all available reporting periods. On-time rates exclude cancelled and diverted flights.

Read our methodology - how this data is sourced, computed, and verified.

Using ISP's data

ISP's on-time book sits in the slower half of the BTS set; check the delay mix and the worst month before treating the headline as typical.

  • Check the busiest route from ISP before you book a connection. See top routes
  • Travel in November rather than July if your dates are flexible. Seasonal patterns
  • Gate-to-wheels taxi-out averages 12.4 min here; check the monthly series before a tight connection. Taxi times

On-time rate reflects the BTS historical average across all reporting carriers at this airport, not any single flight or airline.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights

Source: U.S. Bureau of Transportation Statistics (BTS) Airline on-time performance and operational reliability · 2025

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. Airport figures are computed directly from BTS On-Time Performance data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.