BWI to ISP flight delays
Baltimore, MD (BWI) Islip, NY (ISP) · 220 miles
138 flights · March 2025 – August 2026 · US Bureau of Transportation Statistics
77.37%
Arrived on time
Within 15 minutes of schedule
0.72%
Cancelled
Share of scheduled flights
45 min
When late, late by
Average across delayed arrivals
12 min
Delay per flight
Averaged over every flight flown
What the record says about this route
This route does better than its own airport. Departures from BWI overall run 11.8 points less punctual than this particular one — so whatever congestion BWI has, this route is largely escaping it.
The two directions do not behave alike. ISP to BWI arrives on time 6 points more often than the outbound. Delay accumulates through the flying day, so whichever direction is scheduled later tends to carry the worse record — which is an argument for booking the morning departure if the choice exists.
Only Southwest Airlines flies this route in the published record, so there is no choice to weigh — the route's figures and the airline's are the same figures.
The Baltimore to Islip route sits close to the middle of the record — neither notably punctual nor notably late.
Which airline should you fly on this route?
Over March 2025 – August 2026, Southwest Airlines arrived on time most often on BWI to ISP.
Every airline on BWI to ISP
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 | 138 | 77.37% | 0.72% | 45 min | C |
The return leg
ISP to BWI Islip back to Baltimore 83.33% on time BOther routes from Baltimore
Common questions
Are flights from Baltimore to Islip usually delayed?
77.37% of flights on the BWI to ISP route arrived within 15 minutes of schedule, so roughly 2 in every ten arrived late. That is about the same as the average route in this record.
Which airlines fly from Baltimore to Islip?
Only Southwest Airlines appears in the published record on this route, with 138 flights and 77.37% arriving on time.
How often are BWI to ISP flights cancelled?
0.72% of scheduled flights did not operate — about 7 in every thousand. That is in the normal range.
When BWI to ISP flights are late, how late are they?
About 45 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 BWI to ISP during March 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 →