In terms of precipitation, rainfall in Islip, New York ranges from 3.3 - 4.4 inches per month. March is typically the wettest month, when rainfall can reach 4.4 in. February is typically the driest time to visit Islip, New York when rainfall is around 3.3 in.

If weather is an important factor for your trip to Islip, New York, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 73.4 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 30.2 F).

What is the cheapest time of day to fly from PHL to ISP?

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Philadelphia to Islip, New York as you normally would.

Most accurate provider : When it comes to deals on Philadelphia-Islip, New York flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Philadelphia-Islip, New York flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Philadelphia-Islip, New York flight searches over the past month and is updated monthly.

Most trusted provider : When it comes to deals on Philadelphia-Islip, New York flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Philadelphia-Islip, New York flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Can I find deals for flights from Philadelphia to Islip that include hotel bookings?

Yes. In addition to deals on Philadelphia to Islip flights, Cheapflights offers vacation packages that include both flights and hotel.

How can I find direct flights from Philadelphia to Islip?

After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Philadelphia to Islip.

Can I find deals for business class flights from Philadelphia to Islip?

Yes. Cheapflights offers flight deals from Philadelphia to Islip by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

$194+ Flights from Philadelphia to Islip, NY

Home Search by date Vacation packages Hotels Flight deals Car rental Travel tips & news

Find cheap flights from Philadelphia to Islip with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from Philadelphia to Islip

Cheapest flights from Philadelphia to Islip
Explore the most affordable flight options available from Philadelphia to Islip. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 18, 2025.

Fri 12/1910:00 amPHL - ISP

1 stop9h 40mFrontier

Sun 12/218:35 pmISP - PHL

1 stop12h 02mFrontier

Deal found 12/15

$410

Sat 12/2010:00 pmPHL - ISP

1 stop15h 09mFrontier

Mon 12/228:35 pmISP - PHL

1 stop12h 02mFrontier

Deal found 12/16

$457

Mon 12/226:00 amPHL - ISP

1 stop13h 40mMultiple Airlines

Thu 12/2510:38 amISP - PHL

2 stops27h 26mMultiple Airlines

Deal found 12/17

$513

Sun 12/2810:00 pmPHL - ISP

1 stop15h 09mMultiple Airlines

Mon 12/294:40 pmISP - PHL

1 stop16h 27mMultiple Airlines

Deal found 12/16

$525

Mon 12/226:00 amPHL - ISP

1 stop7h 09mFrontier

Thu 12/2512:20 pmISP - PHL

1 stop8h 19mFrontier

Deal found 12/17

$585

Best flights from Philadelphia to Islip
Discover carefully curated flight deals from Philadelphia to Islip that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated December 18, 2025.

Sun 12/2810:00 pmPHL - ISP

1 stop15h 09mMultiple Airlines

Mon 12/294:40 pmISP - PHL

1 stop16h 27mMultiple Airlines

Deal found 12/16

$525

Last-minute flights from Philadelphia to Islip
Discover last-minute flight deals from Philadelphia to Islip. Data last updated December 18, 2025 and is based on user searches.

Fri 12/1910:00 amPHL - ISP

1 stop9h 40mFrontier

Sun 12/218:35 pmISP - PHL

1 stop12h 02mFrontier

Deal found 12/15

$410

Sat 12/2010:00 pmPHL - ISP

1 stop15h 09mFrontier

Mon 12/228:35 pmISP - PHL

1 stop12h 02mFrontier

Deal found 12/16

$457

Mon 12/226:00 amPHL - ISP

1 stop13h 40mMultiple Airlines

Thu 12/2510:38 amISP - PHL

2 stops27h 26mMultiple Airlines

Deal found 12/17

$513

Mon 12/226:00 amPHL - ISP

1 stop7h 09mFrontier

Thu 12/2512:20 pmISP - PHL

1 stop8h 19mFrontier

Deal found 12/17

$585

Sun 12/2810:00 pmPHL - ISP

1 stop15h 09mMultiple Airlines

Mon 12/294:40 pmISP - PHL

1 stop16h 27mMultiple Airlines

Deal found 12/16

$525

One-way flights from Philadelphia to Islip
Search for one-way flight options from Philadelphia to Islip. Find affordable one-way fares based on user searches. Data last updated December 18, 2025.

Wed 12/248:30 amPHL - ISP

1 stop30h 40mFrontier

Deal found 12/17

$194

Wed 12/246:00 amPHL - ISP

2 stops29h 25mMultiple Airlines

Deal found 12/17

$217

Find flight deals from Philadelphia to Islip

Most accurate provider	eDreams 3 stars
Most trusted provider	eDreams 3 stars
Round-trip from	$457 (Kiwi.com)
One-way from	$194 (Kiwi.com)
Popular in	December
Cheapest in	August
Average price	$554

Provider with most accurate pricing for Philadelphia-Islip Long Island flight deals.

Search Deals

Provider most trusted by Cheapflights users for Philadelphia-Islip Long Island flights.

Search Deals

From Philadelphia to Islip Long Island

Search Deals

One-way flight from Philadelphia to Islip Long Island

Search Deals

Highest demand for flights based on searches. 23% potential increase in price ($102 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 5% potential price decrease ($20 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in December 2025

Search Deals

Cheapflights Fare Finder

Use the filters below to find and compare flights from Philadelphia to Islip that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

PhiladelphiaIslip

PHL - ISP

PHLISP

Philadelphia

Sun 12/28

10:00 pm-1:09 pm

1 stop15h 09m

Islip Long Island

Mon 12/29

4:40 pm-9:07 am

1 stop16h 27m

$525

PhiladelphiaIslip

PHL - ISP

PHLISP

Philadelphia

Wed 12/24

8:30 am-3:10 pm

1 stop30h 40m

$194

PhiladelphiaIslip

PHL - ISP

PHLISP

Philadelphia

Wed 12/24

6:00 am-11:25 am

2 stops29h 25m

$217

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/17

Compare providers for flights from Philadelphia to Islip

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Philadelphia to Islip in December.

Provider	Price Accuracy	Trust Score*
Expedia	Price Accuracy2 stars	Trust Score*3 stars
FlightHub	Price Accuracy3 stars	Trust Score*1 star
eDreams	Price Accuracy3 stars	Trust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

Most accurate provider: When it comes to deals on Philadelphia-Islip, New York flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Philadelphia-Islip, New York flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Philadelphia-Islip, New York flight searches over the past month and is updated monthly.
Most trusted provider: When it comes to deals on Philadelphia-Islip, New York flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Philadelphia-Islip, New York flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Philadelphia to Islip

Have a flexible travel schedule? Discover the best time to fly to Islip from Philadelphia with our price prediction graph.

Estimated round-trip price

Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Philadelphia to Islip

What is the cheapest month to book a flight from Philadelphia to Islip, New York?

Currently, May is the cheapest month in which you can book a flight from Philadelphia to Islip, New York (average of $155). Flying from Philadelphia to Islip, New York in October is currently the most expensive (average of $496). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

Related info for your journey

Can I find deals for flights from Philadelphia to Islip that include hotel bookings?
Yes. In addition to deals on Philadelphia to Islip flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Philadelphia to Islip?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Philadelphia to Islip.
Can I find deals for business class flights from Philadelphia to Islip?
Yes. Cheapflights offers flight deals from Philadelphia to Islip by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.
What is the cheapest month to book a flight from Philadelphia to Islip, New York?
Currently, May is the cheapest month in which you can book a flight from Philadelphia to Islip, New York (average of $155). Flying from Philadelphia to Islip, New York in October is currently the most expensive (average of $496). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Riverhead

Browse thousands of different options on Cheapflights for your next trip

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.

$194+ Cheap flights from Philadelphia to Islip, NY (PHL - ISP)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/24. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Philadelphia to Islip with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheap flight deals from Philadelphia to Islip

Cheapest flights from Philadelphia to IslipExplore the most affordable flight options available from Philadelphia to Islip. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 18, 2025.

Explore the most affordable flight options available from Philadelphia to Islip. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 18, 2025.

Find flight deals from Philadelphia to Islip

Most accurate provider

Most trusted provider

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Cheapflights Fare Finder

Use the filters below to find and compare flights from Philadelphia to Islip that are best for you.

Compare providers for flights from Philadelphia to Islip

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Philadelphia to Islip in December.

Best time to book a flight from Philadelphia to Islip

Have a flexible travel schedule? Discover the best time to fly to Islip from Philadelphia with our price prediction graph.

Cheapflights Insights

Everything you need to know about your flight from Philadelphia to Islip

What is the cheapest month to book a flight from Philadelphia to Islip, New York?

Related info for your journey

Find useful and relevant information for your journey from Philadelphia to Islip. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

Can I find deals for flights from Philadelphia to Islip that include hotel bookings?

How can I find direct flights from Philadelphia to Islip?

Can I find deals for business class flights from Philadelphia to Islip?

What is the cheapest month to book a flight from Philadelphia to Islip, New York?

Traveling to a place near Islip?

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Philadelphia to Islip

See prices for flight routes from nearby airports that may be better suited for you.

100% Free

Book with Flexibility

Travel Smart

Cheapest flights from Philadelphia to Islip
Explore the most affordable flight options available from Philadelphia to Islip. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 18, 2025.