Trip.com
>
Flights
>
Flights to United States
>
Flights to District of Columbia
>
Flights to Washington D.C.
Hotels in Washington D.C.
>
Flights from Islip to Washington D.C.

Find flight deals from Islip to Washington D.C. for the next 3 months. Book one way flights from QAR 246 or round trip flights from QAR 1,022.

      • ISP 4:05 PM
        16h 21m
        1 stop
        IAD 8:26 AM
        Islip - Washington D.C. | Sun, Dec 14 | Frontier Airlines
        IAD 9:26 AM
        14h 33m
        1 stop
        ISP 11:59 PM
        Washington D.C. - Islip | Tue, Dec 16 | Frontier Airlines
        QAR 1,022 QAR 2,420
        57% OFF
        57% OFF
        QAR 2,420 QAR 1,022
      • ISP 12:25 PM
        6h 53m
        1 stop
        DCA 7:18 PM
        Islip - Washington D.C. | Wed, Feb 4 | Jetblue Airways
        DCA 12:15 PM
        20h 40m
        1 stop
        ISP 8:55 AM
        Washington D.C. - Islip | Thu, Feb 5 | Jetblue Airways
        QAR 1,140 QAR 2,420
        53% OFF
        53% OFF
        QAR 2,420 QAR 1,140
      • ISP 6:40 PM
        26h 23m
        1 stop
        IAD 9:03 PM
        Islip - Washington D.C. | Sun, Dec 21 | Frontier Airlines
        IAD 10:15 PM
        14h 54m
        1 stop
        ISP 1:09 PM
        Washington D.C. - Islip | Sun, Dec 28 | Frontier Airlines
        QAR 1,273 QAR 2,420
        47% OFF
        47% OFF
        QAR 2,420 QAR 1,273
      • ISP 12:25 PM
        10h 6m
        1 stop
        DCA 10:31 PM
        Islip - Washington D.C. | Thu, Jan 15 | Jetblue Airways
        DCA 6:30 PM
        17h 5m
        1 stop
        ISP 11:35 AM
        Washington D.C. - Islip | Wed, Jan 21 | Jetblue Airways
        QAR 1,416
        42% OFF
        QAR 2,420 QAR 1,416
      • ISP 1:27 PM
        10h 2m
        1 stop
        DCA 11:29 PM
        Islip - Washington D.C. | Sat, Dec 20 | Frontier Airlines
        DCA 6:40 AM
        13h
        1 stop
        ISP 7:40 PM
        Washington D.C. - Islip | Tue, Dec 23 | American Airlines
        QAR 1,555
        36% OFF
        QAR 2,420 QAR 1,555
      • ISP 6:00 AM
        27h 48m
        1 stop
        IAD 9:48 AM
        Islip - Washington D.C. | Fri, Dec 19 | Frontier Airlines
        IAD 9:58 PM
        15h 11m
        1 stop
        ISP 1:09 PM
        Washington D.C. - Islip | Mon, Dec 22 | Frontier Airlines
        QAR 1,761
        27% OFF
        QAR 2,420 QAR 1,761
      • ISP 10:46 AM
        10h 17m
        1 stop
        IAD 9:03 PM
        Islip - Washington D.C. | Tue, Dec 23 | Jetblue Airways
        IAD 9:58 PM
        12h 3m
        1 stop
        ISP 10:01 AM
        Washington D.C. - Islip | Sat, Dec 27 | Frontier Airlines
        QAR 1,971
        19% OFF
        QAR 2,420 QAR 1,971
      • ISP 12:40 PM
        25h 54m
        1 stop
        DCA 2:34 PM
        Islip - Washington D.C. | Sat, Jan 17 | Cape Air
        DCA 6:30 PM
        17h 5m
        1 stop
        ISP 11:35 AM
        Washington D.C. - Islip | Tue, Jan 20 | Jetblue Airways
        QAR 2,091
        14% OFF
        QAR 2,420 QAR 2,091
      • ISP 9:40 AM
        8h 20m
        1 stop
        DCA 6:00 PM
        Islip - Washington D.C. | Sat, Jan 17 | Jetblue Airways
        DCA 6:30 PM
        17h 5m
        1 stop
        ISP 11:35 AM
        Washington D.C. - Islip | Tue, Jan 20 | Jetblue Airways
        QAR 2,129
        12% OFF
        QAR 2,420 QAR 2,129
      • ISP 7:40 PM
        13h 24m
        1 stop
        DCA 9:04 AM
        Islip - Washington D.C. | Mon, Dec 22 | Jetblue Airways
        DCA 7:00 AM
        27h 1m
        1 stop
        ISP 10:01 AM
        Washington D.C. - Islip | Fri, Dec 26 | Jetblue Airways
        QAR 2,178
        10% OFF
        QAR 2,420 QAR 2,178
      • ISP 1:00 PM
        17h 25m
        1 stop
        WAS Invalid Date
        Islip - Washington D.C. | Sat, Dec 13 | Normal Airline
        WAS 3:00 PM
        6h
        Nonstop
        ISP 4:00 PM
        Washington D.C. - Islip | Mon, Dec 15 | Normal Airline
        Find More Flights
        Find More Flights
      • ISP 3:34 PM
        23h 4m
        1 stop
        IAD 2:38 PM
        Islip - Washington D.C. | Sun, Jan 11 | Frontier Airlines
        QAR 246 QAR 1,099
        78% OFF
        78% OFF
        QAR 1,099 QAR 246
      • ISP 6:15 AM
        13h 52m
        1 stop
        DCA 8:07 PM
        Islip - Washington D.C. | Wed, Dec 17 | Frontier Airlines
        QAR 305 QAR 1,099
        72% OFF
        72% OFF
        QAR 1,099 QAR 305
      • ISP 4:40 PM
        25h 55m
        1 stop
        DCA 6:35 PM
        Islip - Washington D.C. | Sun, Dec 21 | Frontier Airlines
        QAR 423 QAR 1,099
        62% OFF
        62% OFF
        QAR 1,099 QAR 423
      • ISP 9:09 PM
        10h 26m
        1 stop
        IAD 7:35 AM
        Islip - Washington D.C. | Sun, Dec 14 | Frontier Airlines
        QAR 465
        57% OFF
        QAR 1,099 QAR 465
      • ISP 11:50 AM
        10h 49m
        1 stop
        DCA 10:39 PM
        Islip - Washington D.C. | Wed, Dec 17 | Jetblue Airways
        QAR 476
        56% OFF
        QAR 1,099 QAR 476
      • ISP 8:35 PM
        24h 28m
        1 stop
        IAD 9:03 PM
        Islip - Washington D.C. | Mon, Dec 22 | Frontier Airlines
        QAR 496
        55% OFF
        QAR 1,099 QAR 496
      • ISP 9:40 AM
        28h 58m
        1 stop
        IAD 2:38 PM
        Islip - Washington D.C. | Sun, Jan 11 | Jetblue Airways
        QAR 508
        54% OFF
        QAR 1,099 QAR 508
      • ISP 5:45 AM
        14h 11m
        1 stop
        DCA 7:56 PM
        Islip - Washington D.C. | Sat, Dec 20 | Frontier Airlines
        QAR 514
        53% OFF
        QAR 1,099 QAR 514
      • ISP 6:15 AM
        10h 45m
        1 stop
        DCA 5:00 PM
        Islip - Washington D.C. | Fri, Dec 12 | Frontier Airlines
        QAR 531
        52% OFF
        QAR 1,099 QAR 531
      • ISP 12:37 PM
        19h 49m
        1 stop
        IAD 8:26 AM
        Islip - Washington D.C. | Thu, Dec 11 | Frontier Airlines
        QAR 989
        10% OFF
        QAR 1,099 QAR 989
      • ISP 1:00 PM
        17h 25m
        1 stop
        WAS Invalid Date
        Islip - Washington D.C. | Sat, Dec 13 | Normal Airline
        Find More Flights
        Find More Flights

Displayed flight fares from Islip to Washington D.C. are based on average prices across airlines for the next 3 months, according to the latest Trip.com database.

Flying from Islip to Washington D.C.

The distance between Islip and Washington D.C. is approximately 397.38 km. Based on Trip.com's data travel demand peaks in July. The off-season for travel is September.

Cheapest one-way flight priceQAR 246
Cheapest round-trip ticket priceQAR 1,022
Off-season for travelSeptember
Peak season for travelJuly
Flight distance397.38 km

When is the cheapest time to fly from Islip to Washington D.C.?

The cheapest time for Islip to Washington D.C. flights: Jan 4 to Jan 11 — one way flight prices from QAR 246.

Cheapest flights
From price
Search
  • 714
  • 1421
  • 2128

  • Jan

    284
  • 411
  • 1118
  • 1825

  • Feb

    251
  • 18
  • 815
  • 1522

  • Mar

    221
Displayed fare trends are based on Trip.com's aggregated average of the lowest flight prices from Islip to Washington D.C., calculated over the upcoming 10 weeks.

Frequently Asked Questions

  • What are the cheapest flights from Islip to Washington D.C. (ISP-WAS)?

    Based on Trip.com data, Frontier Airlines offers one-way fares as low as QAR 246 on Cheapest nonstop routes (e.g. ISP to IAD on Sun, Jan 11), while Frontier Airlines offers Cheapest nonstop round-trips from QAR 1,022 departing on Sun, Dec 14 and returning on Tue, Dec 16.
  • By analyzing data from all airlines on the Trip.com flight calendar, it looks like the best time to book a flight from Islip to Washington D.C. 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.
  • To find best deals on flights from Islip to Washington D.C., you can use various tools on Trip.com:
    · Be flexible with your travel dates to get the cheapest flight deal. Now the cheapest flight deal is on Sun, Jan 11, with one-way flights priced at just QAR 246.
    · Compare airlines strategically. Budget carriers often provide the lowest base fares, while we found the most affordable airline currently operating on this route is Frontier Airlines.
    · Set up price alerts to easily monitor ticket prices without having to check every day.
    · Check Trip.com flight deals and promo codes frequently.
    · Avoid peak season unless you book very early. It seems the peak season for Washington D.C. travel is around July.
    · Get exclusive promo codes for Trip.com app users.
  • The cheapest months to fly from Islip to Washington D.C. is September, when demand for travel is lower.
  • After crunching the numbers on our December flight calendar, it's currently cheapest to fly from Islip to Washington D.C. on December 13, 2025 with Frontier Airlines, with prices starting at QAR 1,021.
  • The time difference between Washington D.C. and Islip is 0h.
  • 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.

Explore More Popular Flights