Flights from Portland(PDX) to Long Island Macarthur Airport(ISP)

By analyzing data from all airlines on the Trip.com flight calendar, it looks like the best time to book a flight from Portland to Islip is around 40 days (6 weeks) in advance, and the best time to fly is usually on Tuesday, Wednesday, and Saturday. Tuesday typically offers the cheapest flights for departure, while Saturday offers the best return deals.

The cheapest months to fly from Portland to Islip is August, when demand for travel is lower.

After crunching the numbers on our August flight calendar, it's currently cheapest to fly from Portland to Islip on August 14, 2026 with Jetblue Airways, with prices starting at US$910.

The time difference between Islip and Portland is 3h.

Tickets can only be changed or canceled if permitted by airline policy. To submit a change or cancellation request, go to the flight bookings page, select the option to change or cancel your booking, choose the relevant passengers and segment, and submit a request. Please note that additional charges may apply according to the airline ticket policy. However, if the flight has been rescheduled and you would like to change or cancel your ticket, you can submit an involuntary cancellation request. For more details about change and cancellation policies, please check the customer support pages.