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WanderNerd

Airport Reliability

ISP · Islip

Islip, NY (ISP)

75%
Departures within 15 minutes
16 min
Average departure delay
75%
Arrivals within 15 minutes
2.0%
Departures cancelled

Based on 5,020 departures and 5,019 arrivals. Data through May 2026.

What the data says

Morning flights do better here.

Departures from ISP departing between 3–6 AM arrived on time 93% of the time, versus 57% between 6–9 PM.

Sunday scaries are real for this one.

Departures from ISP arrived on time 78% of the time on Wednesdays. On Sundays: 71%.

Trending in the right direction.

Departures from ISP arrived on time 78% of the time over the last three months in the data, compared with 70% in the three months before that.

When ISP gets messy

On-time by departure window
  • 3–6 AM93%(254 flights)
  • 6–9 AM87%(1020 flights)
  • 9 AM–12 PM83%(832 flights)
  • 12–3 PM71%(1162 flights)
  • 3–6 PM67%(1221 flights)
  • 6–9 PM57%(366 flights)
  • 9 PM–12 AM91%(44 flights)
On-time by weekday
  • Mon74%(708 flights)
  • Tue77%(629 flights)
  • Wed78%(660 flights)
  • Thu76%(693 flights)
  • Fri75%(751 flights)
  • Sat76%(749 flights)
  • Sun71%(709 flights)
On-time trend by month
84%
May

Jun 72% → May 84% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202572%445
July 202570%450
August 202573%399
September 202585%348
October 202585%361
November 202578%391
December 202565%446
January 202671%414
February 202673%402
March 202672%395
April 202678%457
May 202684%391

Airlines departing ISP

Based on 5,020 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.