Travelers have found it’s best to book a flight 28 days in advance to save up to 11% compared to booking the same week of travel. As your travel date approaches, the cost of this flight route may potentially increase. While opting to book 28 days out may not be an option for all, there are still additional ways to secure a deal in the near future. You might find a flight from Islip to Washington Dulles Intl 1-2 weeks in advance for as low as $252, or $276 for flights within the next 24 hours.
Flights from Islip to Washington Dulles Intl lean towards being more expensive in December. Prices are generally better when you fly from Islip to Washington Dulles Intl in February, with the cheapest ticket starting at $119.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Islip to Washington Dulles Intl as you normally would.