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Flights from Islip to Washington D.C.

Find the cheapest flight options from Islip to Washington D.C. over the next three months. Book one-way tickets from Rs 18,919 and round-trip tickets from Rs 78,614.

      • ISP 16:05
        16h 21m
        1 stop
        IAD 08:26
        Islip - Washington D.C. | Sun, Dec 14 | Frontier Airlines
        IAD 09:26
        14h 33m
        1 stop
        ISP 23:59
        Washington D.C. - Islip | Tue, Dec 16 | Frontier Airlines
        Rs 78,614 Rs 186,223
        57% OFF
        57% OFF
        Rs 186,223 Rs 78,614
      • ISP 12:25
        6h 53m
        1 stop
        DCA 19:18
        Islip - Washington D.C. | Wed, Feb 4 | Jetblue Airways
        DCA 12:15
        20h 40m
        1 stop
        ISP 08:55
        Washington D.C. - Islip | Thu, Feb 5 | Jetblue Airways
        Rs 87,676 Rs 186,223
        53% OFF
        53% OFF
        Rs 186,223 Rs 87,676
      • ISP 18:40
        26h 23m
        1 stop
        IAD 21:03
        Islip - Washington D.C. | Sun, Dec 21 | Frontier Airlines
        IAD 22:15
        14h 54m
        1 stop
        ISP 13:09
        Washington D.C. - Islip | Sun, Dec 28 | Frontier Airlines
        Rs 97,930 Rs 186,223
        47% OFF
        47% OFF
        Rs 186,223 Rs 97,930
      • ISP 12:25
        10h 6m
        1 stop
        DCA 22:31
        Islip - Washington D.C. | Thu, Jan 15 | Jetblue Airways
        DCA 18:30
        17h 5m
        1 stop
        ISP 11:35
        Washington D.C. - Islip | Wed, Jan 21 | Jetblue Airways
        Rs 108,939
        42% OFF
        Rs 186,223 Rs 108,939
      • ISP 13:27
        10h 2m
        1 stop
        DCA 23:29
        Islip - Washington D.C. | Sat, Dec 20 | Frontier Airlines
        DCA 06:40
        13h
        1 stop
        ISP 19:40
        Washington D.C. - Islip | Tue, Dec 23 | American Airlines
        Rs 119,670
        36% OFF
        Rs 186,223 Rs 119,670
      • ISP 06:00
        27h 48m
        1 stop
        IAD 09:48
        Islip - Washington D.C. | Fri, Dec 19 | Frontier Airlines
        IAD 21:58
        15h 11m
        1 stop
        ISP 13:09
        Washington D.C. - Islip | Mon, Dec 22 | Frontier Airlines
        Rs 135,488
        27% OFF
        Rs 186,223 Rs 135,488
      • ISP 10:46
        10h 17m
        1 stop
        IAD 21:03
        Islip - Washington D.C. | Tue, Dec 23 | Jetblue Airways
        IAD 21:58
        12h 3m
        1 stop
        ISP 10:01
        Washington D.C. - Islip | Sat, Dec 27 | Frontier Airlines
        Rs 151,624
        19% OFF
        Rs 186,223 Rs 151,624
      • ISP 12:40
        25h 54m
        1 stop
        DCA 14:34
        Islip - Washington D.C. | Sat, Jan 17 | Cape Air
        DCA 18:30
        17h 5m
        1 stop
        ISP 11:35
        Washington D.C. - Islip | Tue, Jan 20 | Jetblue Airways
        Rs 160,884
        14% OFF
        Rs 186,223 Rs 160,884
      • ISP 09:40
        8h 20m
        1 stop
        DCA 18:00
        Islip - Washington D.C. | Sat, Jan 17 | Jetblue Airways
        DCA 18:30
        17h 5m
        1 stop
        ISP 11:35
        Washington D.C. - Islip | Tue, Jan 20 | Jetblue Airways
        Rs 163,786
        12% OFF
        Rs 186,223 Rs 163,786
      • ISP 19:40
        13h 24m
        1 stop
        DCA 09:04
        Islip - Washington D.C. | Mon, Dec 22 | Jetblue Airways
        DCA 07:00
        27h 1m
        1 stop
        ISP 10:01
        Washington D.C. - Islip | Fri, Dec 26 | Jetblue Airways
        Rs 167,601
        10% OFF
        Rs 186,223 Rs 167,601
      • ISP 13:00
        17h 25m
        1 stop
        WAS Invalid Date
        Islip - Washington D.C. | Sat, Dec 13 | Normal Airline
        WAS 15:00
        6h
        Direct
        ISP 16:00
        Washington D.C. - Islip | Mon, Dec 15 | Normal Airline
        Find More Flights
        Find More Flights
      • ISP 15:34
        23h 4m
        1 stop
        IAD 14:38
        Islip - Washington D.C. | Sat, Jan 10 | Frontier Airlines
        Rs 18,919 Rs 45,353
        57% OFF
        57% OFF
        Rs 45,353 Rs 18,919
      • ISP 06:15
        13h 52m
        1 stop
        DCA 20:07
        Islip - Washington D.C. | Tue, Dec 16 | Frontier Airlines
        Rs 23,410 Rs 45,353
        48% OFF
        48% OFF
        Rs 45,353 Rs 23,410
      • ISP 16:40
        25h 55m
        1 stop
        DCA 18:35
        Islip - Washington D.C. | Sat, Dec 20 | Frontier Airlines
        Rs 32,511 Rs 45,353
        28% OFF
        28% OFF
        Rs 45,353 Rs 32,511
      • ISP 21:09
        10h 26m
        1 stop
        IAD 07:35
        Islip - Washington D.C. | Sat, Dec 13 | Frontier Airlines
        Rs 35,730
        21% OFF
        Rs 45,353 Rs 35,730
      • ISP 11:50
        10h 49m
        1 stop
        DCA 22:39
        Islip - Washington D.C. | Tue, Dec 16 | Jetblue Airways
        Rs 36,565
        19% OFF
        Rs 45,353 Rs 36,565
      • ISP 20:35
        24h 28m
        1 stop
        IAD 21:03
        Islip - Washington D.C. | Sun, Dec 21 | Frontier Airlines
        Rs 38,115
        16% OFF
        Rs 45,353 Rs 38,115
      • ISP 09:40
        28h 58m
        1 stop
        IAD 14:38
        Islip - Washington D.C. | Sat, Jan 10 | Jetblue Airways
        Rs 39,029
        14% OFF
        Rs 45,353 Rs 39,029
      • ISP 05:45
        14h 11m
        1 stop
        DCA 19:56
        Islip - Washington D.C. | Fri, Dec 19 | Frontier Airlines
        Rs 39,506
        13% OFF
        Rs 45,353 Rs 39,506
      • ISP 05:45
        12h 9m
        1 stop
        DCA 17:54
        Islip - Washington D.C. | Thu, Dec 18 | Frontier Airlines
        Rs 39,705
        12% OFF
        Rs 45,353 Rs 39,705
      • ISP 06:15
        10h 45m
        1 stop
        DCA 17:00
        Islip - Washington D.C. | Thu, Dec 11 | Frontier Airlines
        Rs 40,818
        10% OFF
        Rs 45,353 Rs 40,818
      • ISP 13:00
        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.

Flight details for Islip to Washington D.C.

The distance between Islip and Washington D.C. is 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 priceRs 18,919
Cheapest round-trip ticket priceRs 78,614
Off-season for travelSeptember
Peak season for travelJuly
Flight distance397.38 km

Find the best 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 Rs 18,918.

Cheapest flights
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  • 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.

Flight FAQs

  • 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 Rs 18,919 on Cheapest nonstop routes (e.g. ISP to IAD on Sat, Jan 10), while Frontier Airlines offers Cheapest nonstop round-trips from Rs 78,614 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 Sat, Jan 10, with one-way flights priced at just Rs 18,919.
    · 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 Rs 78,613.
  • 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.