ISP to PBI flight delays
Islip, NY (ISP) West Palm Beach/Palm Beach, FL (PBI) · 1,052 miles
1,223 flights · January 2025 – August 2026 · US Bureau of Transportation Statistics
71.91%
Arrived on time
Within 15 minutes of schedule
2.13%
Cancelled
Share of scheduled flights
70 min
When late, late by
Average across delayed arrivals
21 min
Delay per flight
Averaged over every flight flown
What the record says about this route
The season swings this route hard. In June it ran 28.8 points more punctual than in December — a difference bigger than the one between the best and worst airlines on most routes. If the date is flexible, it is worth more than the carrier.
Flights from Islip to West Palm Beach/Palm Beach run late more often than the average route, though not severely.
The 2 airlines here are separated by under 2 points — close enough to call a tie. Choose on price and departure time.
Which airline should you fly on this route?
Over January 2025 – August 2026, JetBlue Airways arrived on time most often on ISP to PBI. Southwest Airlines was late most often. Flights ran closest to schedule in June and worst in December.
Every airline on ISP to PBI
Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.
| Airline | Flights | On time | Cancelled | Avg delay | Grade |
|---|---|---|---|---|---|
| Southwest Airlines | 611 | 71.4% | 1.64% | 50 min | D |
| JetBlue Airways | 541 | 72.66% | 2.4% | 93 min | D |
| Frontier Airlines | 71 | 70.59% | 4.23% | 86 min | — |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
Common questions
Are flights from Islip to West Palm Beach/Palm Beach usually delayed?
71.91% of flights on the ISP to PBI route arrived within 15 minutes of schedule, so roughly 3 in every ten arrived late. That is worse than the average route in this record.
Which airline is most on time from Islip to West Palm Beach/Palm Beach?
JetBlue Airways, at 72.66% on time across 541 flights. The least punctual on the route was Southwest Airlines at 71.4%.
How often are ISP to PBI flights cancelled?
2.13% of scheduled flights did not operate — about 21 in every thousand. That is in the normal range.
What is the best month to fly Islip to West Palm Beach/Palm Beach?
June, when 86.1% of flights arrived on time. The worst was December at 57.3%.
When ISP to PBI flights are late, how late are they?
About 70 minutes on average across the flights that arrived more than 15 minutes behind schedule.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on ISP to PBI during January 2025 – August 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.
A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.
Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →