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Flights from Islip to San Francisco

Find the cheapest flight options from Islip to San Francisco over the next three months. Book one-way tickets from HK$1,540 and round-trip tickets from HK$3,970.

      • ISP 15:34
        31h 1m
        1 stop
        SFO 19:35
        Islip - San Francisco | Tue, Jan 6 | Frontier Airlines
        SFO 22:50
        12h 49m
        1 stop
        ISP 14:39
        San Francisco - Islip | Sun, Jan 11 | United Airlines
        HK$3,970 HK$9,963
        60% OFF
        60% OFF
        HK$9,963 HK$3,970
      • ISP 14:04
        12h 6m
        1 stop
        SFO 23:10
        Islip - San Francisco | Sun, Dec 21 | Frontier Airlines
        SFO 23:07
        11h 2m
        1 stop
        ISP 13:09
        San Francisco - Islip | Sun, Dec 28 | Hawaiian Airlines
        HK$4,937 HK$9,963
        50% OFF
        50% OFF
        HK$9,963 HK$4,937
      • ISP 07:30
        10h 21m
        1 stop
        SFO 14:51
        Islip - San Francisco | Tue, Jan 6 | Cape Air
        SFO 23:25
        8h 39m
        1 stop
        ISP 11:04
        San Francisco - Islip | Sun, Jan 11 | United Airlines
        HK$7,057 HK$9,963
        28% OFF
        28% OFF
        HK$9,963 HK$7,057
      • ISP 09:59
        28h 51m
        1 stop
        SFO 11:50
        Islip - San Francisco | Sun, Jan 4 | Cape Air
        SFO 07:10
        9h 35m
        1 stop
        ISP 19:45
        San Francisco - Islip | Sun, Jan 11 | Delta Air Lines
        HK$7,763
        22% OFF
        HK$9,963 HK$7,763
      • ISP 12:30
        14h 29m
        1 stop
        SFO 23:59
        Islip - San Francisco | Sat, Dec 13 | Cape Air
        SFO 07:00
        25h 5m
        1 stop
        ISP 11:05
        San Francisco - Islip | Thu, Dec 18 | Delta Air Lines
        HK$8,007
        20% OFF
        HK$9,963 HK$8,007
      • ISP 09:59
        28h 38m
        1 stop
        SFO 11:37
        Islip - San Francisco | Mon, Dec 22 | Cape Air
        SFO 07:30
        24h 35m
        1 stop
        ISP 11:05
        San Francisco - Islip | Fri, Dec 26 | Delta Air Lines
        HK$8,867
        11% OFF
        HK$9,963 HK$8,867
      • ISP 13:00
        17h 25m
        1 stop
        SFO Invalid Date
        Islip - San Francisco | Fri, Dec 12 | Normal Airline
        SFO 15:00
        6h
        Direct
        ISP 16:00
        San Francisco - Islip | Sun, Dec 14 | Normal Airline
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Displayed flight fares from Islip to San Francisco are based on average prices across airlines for the next 3 months, according to the latest Trip.com database.

Flight details for Islip to San Francisco

The distance between Islip and San Francisco is 4,205.68km. Based on Trip.com's data, travel demand peaks in July. The off-season for travel is October.

Cheapest one-way flight priceHK$1,540
Cheapest return ticket priceHK$3,970
Off-season travel monthOctober
Peak season for travelJuly
Flight distance4,205.68km

Find the best time to fly from Islip to San Francisco

The cheapest time for Islip to San Francisco flights: Jan 25 to Feb 1 — one way flight prices from HK$1,048.

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 San Francisco, calculated over the upcoming 10 weeks.

Flight FAQs

  • Which airlines offer the cheapest flights from Islip (ISP) to San Francisco (SFO)?

    Based on Trip.com data, Jetblue Airways offers one-way fares as low as HK$1,540 on Cheapest nonstop routes (e.g. ISP to SFO on Wed, Dec 10), while Frontier Airlines offers Cheapest nonstop round-trips from HK$3,970 departing on Tue, Jan 6 and returning on Sun, Jan 11.
  • 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 San Francisco 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 San Francisco, 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 Wed, Dec 10, with one-way flights priced at just HK$1,540.
    · Compare airlines strategically. Budget carriers often provide the lowest base fares, while we found the most affordable airline currently operating on this route is Jetblue Airways.
    · 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 San Francisco travel is around July.
    · Get exclusive promo codes for Trip.com app users.
  • The cheapest months to fly from Islip to San Francisco is October, when demand for travel is lower.
  • After crunching the numbers on our December flight calendar, it's currently cheapest to fly from Islip to San Francisco on December 21, 2025 with Frontier Airlines, with prices starting at HK$4,936.
  • The time difference between San Francisco and Islip is 3h.
  • 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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