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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 PHP 3,980 and round-trip tickets from PHP 16,539.

      • ISP 16:05
        16h 21m
        1 stop
        IAD 08:26
        Islip - Washington D.C. | Sat, Dec 13 | Frontier Airlines
        IAD 09:26
        14h 33m
        1 stop
        ISP 23:59
        Washington D.C. - Islip | Mon, Dec 15 | Frontier Airlines
        PHP 16,539 PHP 39,177
        57% OFF
        57% OFF
        PHP 39,177 PHP 16,539
      • ISP 12:25
        6h 53m
        1 stop
        DCA 19:18
        Islip - Washington D.C. | Tue, Feb 3 | Jetblue Airways
        DCA 12:15
        20h 40m
        1 stop
        ISP 08:55
        Washington D.C. - Islip | Wed, Feb 4 | Jetblue Airways
        PHP 18,445 PHP 39,177
        53% OFF
        53% OFF
        PHP 39,177 PHP 18,445
      • ISP 18:40
        26h 23m
        1 stop
        IAD 21:03
        Islip - Washington D.C. | Sat, Dec 20 | Frontier Airlines
        IAD 22:15
        14h 54m
        1 stop
        ISP 13:09
        Washington D.C. - Islip | Sat, Dec 27 | Frontier Airlines
        PHP 20,603 PHP 39,177
        47% OFF
        47% OFF
        PHP 39,177 PHP 20,603
      • ISP 12:25
        10h 6m
        1 stop
        DCA 22:31
        Islip - Washington D.C. | Wed, Jan 14 | Jetblue Airways
        DCA 18:30
        17h 5m
        1 stop
        ISP 11:35
        Washington D.C. - Islip | Tue, Jan 20 | Jetblue Airways
        PHP 22,919
        42% OFF
        PHP 39,177 PHP 22,919
      • ISP 13:27
        10h 2m
        1 stop
        DCA 23:29
        Islip - Washington D.C. | Fri, Dec 19 | Frontier Airlines
        DCA 06:40
        13h
        1 stop
        ISP 19:40
        Washington D.C. - Islip | Mon, Dec 22 | American Airlines
        PHP 25,176
        36% OFF
        PHP 39,177 PHP 25,176
      • ISP 06:00
        27h 48m
        1 stop
        IAD 09:48
        Islip - Washington D.C. | Thu, Dec 18 | Frontier Airlines
        IAD 21:58
        15h 11m
        1 stop
        ISP 13:09
        Washington D.C. - Islip | Sun, Dec 21 | Frontier Airlines
        PHP 28,504
        27% OFF
        PHP 39,177 PHP 28,504
      • ISP 10:46
        10h 17m
        1 stop
        IAD 21:03
        Islip - Washington D.C. | Mon, Dec 22 | Jetblue Airways
        IAD 21:58
        12h 3m
        1 stop
        ISP 10:01
        Washington D.C. - Islip | Fri, Dec 26 | Frontier Airlines
        PHP 31,898
        19% OFF
        PHP 39,177 PHP 31,898
      • ISP 12:40
        25h 54m
        1 stop
        DCA 14:34
        Islip - Washington D.C. | Fri, Jan 16 | Cape Air
        DCA 18:30
        17h 5m
        1 stop
        ISP 11:35
        Washington D.C. - Islip | Mon, Jan 19 | Jetblue Airways
        PHP 33,847
        14% OFF
        PHP 39,177 PHP 33,847
      • ISP 09:40
        8h 20m
        1 stop
        DCA 18:00
        Islip - Washington D.C. | Fri, Jan 16 | Jetblue Airways
        DCA 18:30
        17h 5m
        1 stop
        ISP 11:35
        Washington D.C. - Islip | Mon, Jan 19 | Jetblue Airways
        PHP 34,457
        12% OFF
        PHP 39,177 PHP 34,457
      • ISP 19:40
        13h 24m
        1 stop
        DCA 09:04
        Islip - Washington D.C. | Sun, Dec 21 | Jetblue Airways
        DCA 07:00
        27h 1m
        1 stop
        ISP 10:01
        Washington D.C. - Islip | Thu, Dec 25 | Jetblue Airways
        PHP 35,260
        10% OFF
        PHP 39,177 PHP 35,260
      • 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
        PHP 3,980 PHP 9,542
        57% OFF
        57% OFF
        PHP 9,542 PHP 3,980
      • ISP 06:15
        13h 52m
        1 stop
        DCA 20:07
        Islip - Washington D.C. | Tue, Dec 16 | Frontier Airlines
        PHP 4,925 PHP 9,542
        48% OFF
        48% OFF
        PHP 9,542 PHP 4,925
      • ISP 16:40
        25h 55m
        1 stop
        DCA 18:35
        Islip - Washington D.C. | Sat, Dec 20 | Frontier Airlines
        PHP 6,840 PHP 9,542
        28% OFF
        28% OFF
        PHP 9,542 PHP 6,840
      • ISP 21:09
        10h 26m
        1 stop
        IAD 07:35
        Islip - Washington D.C. | Sat, Dec 13 | Frontier Airlines
        PHP 7,517
        21% OFF
        PHP 9,542 PHP 7,517
      • ISP 11:50
        10h 49m
        1 stop
        DCA 22:39
        Islip - Washington D.C. | Tue, Dec 16 | Jetblue Airways
        PHP 7,693
        19% OFF
        PHP 9,542 PHP 7,693
      • ISP 20:35
        24h 28m
        1 stop
        IAD 21:03
        Islip - Washington D.C. | Sun, Dec 21 | Frontier Airlines
        PHP 8,019
        16% OFF
        PHP 9,542 PHP 8,019
      • ISP 09:40
        28h 58m
        1 stop
        IAD 14:38
        Islip - Washington D.C. | Sat, Jan 10 | Jetblue Airways
        PHP 8,211
        14% OFF
        PHP 9,542 PHP 8,211
      • ISP 05:45
        14h 11m
        1 stop
        DCA 19:56
        Islip - Washington D.C. | Fri, Dec 19 | Frontier Airlines
        PHP 8,312
        13% OFF
        PHP 9,542 PHP 8,312
      • ISP 05:45
        12h 9m
        1 stop
        DCA 17:54
        Islip - Washington D.C. | Thu, Dec 18 | Frontier Airlines
        PHP 8,353
        12% OFF
        PHP 9,542 PHP 8,353
      • ISP 06:15
        10h 45m
        1 stop
        DCA 17:00
        Islip - Washington D.C. | Thu, Dec 11 | Frontier Airlines
        PHP 8,587
        10% OFF
        PHP 9,542 PHP 8,587
      • 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 397.38km. Based on Trip.com's data, travel demand peaks in July. The off-season for travel is September.

Cheapest one-way flight pricePHP 3,980
Cheapest return ticket pricePHP 16,539
Off-season travel monthSeptember
Peak season for travelJuly
Flight distance397.38km

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 PHP 3,980.

Cheapest flights
From price
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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

  • Which airlines offer the cheapest flights from Islip (ISP) to Washington D.C. (WAS)?

    Based on Trip.com data, Frontier Airlines offers one-way fares as low as PHP 3,980 on Cheapest nonstop routes (e.g. ISP to IAD on Sat, Jan 10), while Frontier Airlines offers Cheapest nonstop round-trips from PHP 16,539 departing on Sat, Dec 13 and returning on Mon, Dec 15.
  • 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 PHP 3,980.
    · 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 PHP 16,538.
  • The time difference between Washington D.C. and Islip is 0h.
  • Tickets can only be changed or cancelled 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.

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