Our data shows that August tends to be the cheapest month to fly to Islip, New York from Pennsylvania. Users have commonly found prices around $217 for the month, but tickets can be as low as $36. Due to multiple factors, prepare for potentially higher prices in January.
To save up to 80% on this flight, we recommend booking at least 35 days prior to travel. The price may fluctuate and will likely increase closer to your departure date. Users on Cheapflights have found tickets from Pennsylvania to Islip, New York from $184 1-2 weeks out and tickets from $280 for flights departing within the next 72 hours.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Pennsylvania to Islip, New York as you normally would.