$106 Find Cheap Flights from Islip to Puerto Rico

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Islip to Puerto Rico departing on 5/17. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Flight Deals

Book Cheap Islip to Puerto Rico Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Islip to Puerto Rico that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Islip to Puerto Rico

Fri, Jun 5 - Sun, Jun 7
Frontier Logo
11:00 am - 11:22 pm
ISP
-
SJU
12h 22m
1 stop
Frontier Logo
6:00 am - 10:05 am
SJU
-
ISP
28h 05m
1 stop
$212Frontier
Wed, Jul 1 - Thu, Jul 9
Frontier Logo
9:52 pm - 2:09 am
ISP
-
SJU
28h 17m
1 stop
Frontier Logo
3:06 am - 9:58 am
SJU
-
ISP
6h 52m
1 stop
$258Frontier
Fri, Jun 19 - Sun, Jun 21
Frontier Logo
7:50 pm - 12:37 am
ISP
-
SJU
28h 47m
1 stop
Frontier Logo
3:06 am - 8:57 pm
SJU
-
ISP
17h 51m
1 stop
$276Frontier
Mon, May 25 - Fri, Jun 5
Frontier Logo
6:43 pm - 11:59 pm
ISP
-
SJU
29h 16m
1 stop
Frontier Logo
4:46 pm - 5:58 pm
SJU
-
ISP
25h 12m
1 stop
$289Frontier
Sat, Jul 4 - Tue, Jul 7
Frontier Logo
10:48 am - 7:57 am
ISP
-
SJU
21h 09m
1 stop
Frontier Logo
5:22 pm - 7:03 pm
SJU
-
ISP
25h 41m
1 stop
$301Frontier
Wed, Jul 1 - Wed, Jul 8
Frontier Logo
9:52 pm - 7:55 am
ISP
-
SJU
10h 03m
1 stop
Frontier Logo
3:06 am - 10:03 am
SJU
-
ISP
6h 57m
1 stop
$308Frontier
Fri, Aug 14 - Wed, Aug 19
Frontier Logo
7:50 pm - 12:41 am
ISP
-
SJU
28h 51m
1 stop
Frontier Logo
6:00 am - 10:03 am
SJU
-
ISP
28h 03m
1 stop
$315Frontier
Thu, Aug 20 - Mon, Aug 24
Frontier Logo
10:48 am - 11:29 pm
ISP
-
SJU
12h 41m
1 stop
Frontier Logo
3:06 am - 3:56 pm
SJU
-
ISP
12h 50m
1 stop
$321Frontier
Sun, Jun 7 - Sun, Jun 14
Frontier Logo
11:00 am - 2:08 am
ISP
-
SJU
15h 08m
1 stop
Frontier Logo
6:00 am - 8:57 pm
SJU
-
ISP
14h 57m
1 stop
$329Frontier
Sat, Jun 13 - Tue, Jun 16
Frontier Logo
7:50 pm - 12:37 am
ISP
-
SJU
28h 47m
1 stop
Frontier Logo
5:15 pm - 7:05 pm
SJU
-
ISP
25h 50m
1 stop
$343Frontier
Booking Insights

KAYAK's insights & trends for Islip to Puerto Rico flights

Get data-powered insights and trends into flights from Islip to Puerto Rico to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest month to fly from Islip to Puerto Rico?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Islip to Puerto Rico, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Islip to Puerto Rico is January, when tickets cost $106 (return) on average. On the other hand, the most expensive months are February and October, when the average cost of round-trip tickets is $865 and $608 respectively.

Good to know

Low seasonMarch
Cheapest flight$106
Best time to beat the crowds but there is an average 11% increase in price.
Most popular time to fly with an average 26% increase in price.
Flight from Islip to San Juan

FAQs - booking Puerto Rico flights

  • How does KAYAK find such low prices on flights from Islip to Puerto Rico?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Islip to Puerto Rico.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Islip to Puerto Rico?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Islip to Puerto Rico is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Islip to Puerto Rico?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly from Islip to Puerto Rico with an airline and back with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Islip to Puerto Rico?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying from Islip to Puerto Rico up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top airlines flying from Islip to Puerto Rico

 
Need help choosing which airline to fly with from Islip to Puerto Rico? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.9
SouthwestOverall score based on 4305 reviews
8.0Comfort
8.6Crew
7.5Entertainment
8.1Boarding
7.0Food
Airline reviews

Truly terrible. Will never willingly fly southwest again. Seats are worse than before they switched to assigned seating. One flight attendant was the opposite of helpful (rude, unhelpful, dismissive, and as my stranger seatmate said unprompted: a total prick). This caused me, 15 minutes into the flight, to book an alternate return flight home on a competing airline (first class 1.2k purchase instead of my existing planned flight) just so I would not have to ever be on that aircraft, with that terrible service person, with those horrific seats ever again.

2.0 MediocreJoshua, May 2026
TPA - LAS
Read more Southwest reviews

Truly terrible. Will never willingly fly southwest again. Seats are worse than before they switched to assigned seating. One flight attendant was the opposite of helpful (rude, unhelpful, dismissive, and as my stranger seatmate said unprompted: a total prick). This caused me, 15 minutes into the flight, to book an alternate return flight home on a competing airline (first class 1.2k purchase instead of my existing planned flight) just so I would not have to ever be on that aircraft, with that terrible service person, with those horrific seats ever again.

Not having a five hour delay with little notice! The crew was very kind, though, and just as tired as we passengers were. The flight didn't depart until nearly 1 am...and no reason was ever given.

The entire experience from boarding to landing was amazing! The crew were very friendly. Will definitely be back.

no service at all due to turbulence. they should've at least given us snacks, there were only 10 people on the entire flight.

First time I've had to use the disabled accommodations. And I could not have had a better experience with Southwest, i was having trouble getting from one terminal to another due to my heart failure. And the next thing I know a Southwest agent had made sure. I had a wheelchair at all my flights. Can't thank them enough.

Delayed flight, lack of information, boarding process is a mess as is the carryon luggage causing issues when leaving the plane….just a poor experience.

Comfortable. Easy. No problems. Just wish they had gf options for snacks.

The crew was very kind and made going to Hawaii relaxing and fun to look forward to! Thank you Southwest for a pleasant flight!

This leg was much better, but we did have to have a 3 hour lay o er after coming from a very exhausting hiccup with our flight from BNA to Den

We waited in the airplane for over 45 min for a southwest employee to make the flight. This cause over half the plane to miss their connecting flight in Denver. When we confronted the desk upon arrival, they told us the only flight they had was the next day leaving at 8:50 pm!!! Or they offered to get us to Burbank or LA, but after that we were on our own to get back to Santa Barbara. I paid for a flight from sba to bna bna to sba. My re entry into mom mode has been 💯 rough because of southwest mistake with my flight. And now I’m leaving to Reno tomorrow for a vballl tournament and just discovered that my leg in Vegas has me and my 3 kids on a stand by flight even though I had booked these ticket last year November!! Do better southwest!

Frontier scheduled a 40 minute connection in DEN. What they failed to mention was that they “close the doors” 20 mins prior to departure, which means you only have 20 mins. Not enough time. Possibly against DOT regulations. Filing complaint.

Flight was scheduled at 9:40pm. Got delayed to 10 am, the next day. crazy

The bag check, flight check-in, and onboard experience convinced my wife and me that we will actively go out of our way to avoid flying Frontier Airlines in the future. At bag check, we were informed that check-in could only be completed via the Frontier mobile app. Unfortunately, the app was extremely frustrating—sending us through repetitive, confusing loops that repeatedly forced us to decline add-on services with nearly every click. While most airline apps upsell, this one felt intentionally exhausting. As the process dragged on, we became genuinely concerned that my phone battery would die before check-in could be completed. We approached the bag check staff—who were standing together talking—and explained both our frustration and our predicament. They laughed. Later, my wife described the interaction as “gaslighting,” which felt accurate. We were then informed it would cost $25 per person simply to have our boarding passes printed. From that point forward, the tone of the experience was consistently hostile. The bag check employees were condescending and combative, behaving more like bullies than customer service staff. Unfortunately, that same attitude continued onboard. One flight attendant argued with me when I attempted to stow my backpack in the overhead bin. I explained that we had each paid $75 to check our bags specifically so we would not need to use carry-on space and could have adequate legroom. She demanded to see my ticket, pointed out that it said “no carry-on”—which I acknowledged—and I reiterated that this was precisely why we paid to check our bags. Her response was, “I don’t make the rules.” She then walked away, but not before asking if I “truly wanted to fly back to Chicago today?”—an unnecessary and unmistakable threat. It is also worth noting that despite booking our tickets together in the same transaction, we were not seated together. Upon our return to Chicago—where we could once again sit together—we compared onboard experiences. We both remarked on how unhappy the flight attendants appeared and how each of us was separately asked whether we would like to purchase a beverage. We declined. At no point was water mentioned as an option, leaving us with the clear impression that even water came at a cost—or that complimentary water, if available at all, was deliberately left unmentioned. Overall, the experience was shocking and deeply disappointing, but it was also a profound learning experience—one we will not forget and will not repeat. -Steve

Plane was hot and miserable and the crew was rude!

12 hour delay required getting on and off plane 3 times - would have at least liked to have been offered a snack or drink

They didn’t offer a water, even after I asked

They switched our terminal 3 times and we were delayed for four plus hours!!!

It was an early flight and most people napped/slept and the crew let us which was nice.

The crew acted like they had never done this and kept barking passive aggressive orders at people. + the security line + the delay + sitting on the tarmac for 2 hours + none of the apps or signage updating with correct times

More inflight connection. And leg space is horrible. And the paying for baggage I'd ridiculous!!!

Everything you need to know for your flight from Islip to Puerto Rico

Information on your arrival and departure airports