In terms of precipitation, rainfall in Islip 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 when rainfall is around 3.3 in.

If weather is an important factor for your trip to Islip, 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 are the most popular routes from Region of Ontario to Islip?

The most popular flight routes from Region of Ontario to Islip are Ottawa - Islip Long Island, Montreal Pierre Elliott Trudeau Intl - Islip Long Island and Toronto Pearson Intl - Islip Long Island.

How far in advance should I book a flight from Region of Ontario to Islip?

Travelers have found it’s best to book a flight 54 days in advance to save up to 62% compared to booking the same week of travel. As your travel date approaches, the cost of this flight route may potentially increase. While opting to book 54 days out may not be an option for all, there are still additional ways to secure a deal in the near future. You might find a flight from Region of Ontario to Islip 1-2 weeks in advance for as low as $236, or $355 for flights within the next 24 hours.

What is the cheapest month to fly from Region of Ontario to Islip?

Due to multiple factors, expect to potentially pay more when booking in December. For low rates, May can be a great choice for travel to Islip. Flights to Islip from Region of Ontario in May are about $223 on average during May, but can be found for as low as $118.

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

When flying from Region of Ontario to Islip, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

What airport do you fly into for flights to Islip from Ontario?

Most people fly into Islip Long Island (ISP) if they book a flight to Islip from Ontario. Long Island is conveniently located just 7.2 mi from Islip’s city center.

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

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

How can I find direct flights from Ontario to Islip?

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

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

Yes. Cheapflights offers flight deals from Ontario 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.

$230+ Flights from Ontario to Islip

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Cheap flight deals from Ontario to Islip

Round-trip from	$360 (Trip.com)
One-way from	$230 (Kiwi.com)
Popular in	December
Cheapest in	May
Average price	$213

From Ontario to Islip Long Island

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One-way flight from Ontario to Islip Long Island

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Highest demand for flights based on searches. 4% potential increase in price ($10 potential increase over avg. RT price).

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Cheapest flight prices on average. 1% potential price decrease ($4 potential savings vs. average RT price).

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Average for round-trip flights in September 2025

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Find flight deals from Ontario to Islip

Cheapest flights from Ontario to Islip
Explore the most affordable flight options available from Ontario to Islip. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 11, 2025.

Sun 10/264:35 pmYUL - ISP

1 stop18h 02mMultiple Airlines

Sun 11/29:27 pmISP - YUL

1 stop27h 03mMultiple Airlines

Deal found 9/11

$360

Thu 10/97:15 amYYZ - ISP

1 stop13h 27mMultiple Airlines

Thu 10/169:37 pmISP - YYZ

1 stop25h 03mMultiple Airlines

Deal found 9/11

$435

Best flights from Ontario to Islip
Discover carefully curated flight deals from Ontario to Islip that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 11, 2025.

Sun 10/264:35 pmYUL - ISP

1 stop18h 02mMultiple Airlines

Sun 11/29:27 pmISP - YUL

1 stop27h 03mMultiple Airlines

Deal found 9/11

$360

Thu 10/97:15 amYYZ - ISP

1 stop13h 27mMultiple Airlines

Thu 10/169:37 pmISP - YYZ

1 stop25h 03mMultiple Airlines

Deal found 9/11

$435

Last-minute flights from Ontario to Islip
Discover last-minute flight deals from Ontario to Islip. Data last updated September 11, 2025 and is based on user searches.

Thu 10/97:15 amYYZ - ISP

1 stop13h 27mMultiple Airlines

Thu 10/169:37 pmISP - YYZ

1 stop25h 03mMultiple Airlines

Deal found 9/11

$435

Sun 10/264:35 pmYUL - ISP

1 stop18h 02mMultiple Airlines

Sun 11/29:27 pmISP - YUL

1 stop27h 03mMultiple Airlines

Deal found 9/11

$360

One-way flights from Ontario to Islip
Search for one-way flight options from Ontario to Islip. Find affordable one-way fares based on user searches. Data last updated September 11, 2025.

Mon 10/133:00 pmYYZ - ISP

2 stops43h 57mMultiple Airlines

Deal found 9/8

$230

Fri 9/191:10 pmYUL - ISP

2 stops21h 48mMultiple Airlines

Deal found 9/9

$554

Fly from

Fly to

Route

Depart

Return

Price

MontrealIslip

YUL - ISP

YULISP

Montreal Pierre Elliott Trudeau Intl

Sun 10/26

4:35 pm-10:37 am

1 stop18h 02m

Islip Long Island

Sun 11/2

9:27 pm-12:30 am

1 stop27h 03m

$360

TorontoIslip

YYZ - ISP

YYZISP

Toronto Pearson Intl

Thu 10/9

7:15 am-8:42 pm

1 stop13h 27m

Islip Long Island

Thu 10/16

9:37 pm-10:40 pm

1 stop25h 03m

$435

TorontoIslip

YYZ - ISP

YYZISP

Toronto Pearson Intl

Mon 10/13

3:00 pm-10:57 am

2 stops43h 57m

$230

MontrealIslip

YUL - ISP

YULISP

Montreal Pierre Elliott Trudeau Intl

Fri 9/19

1:10 pm-10:58 am

2 stops21h 48m

$554

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/8

Best time to book a flight from Ontario to Islip

Have a flexible travel schedule? Discover the best time to fly to Islip from Ontario 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 Ontario to Islip

What is the cheapest month to book a flight from Region of Ontario to Islip?

Currently, January is the cheapest month in which you can book a flight from Region of Ontario to Islip (average of $108). Flying from Region of Ontario to Islip in November is currently the most expensive (average of $213). 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

What airport do you fly into for flights to Islip from Ontario?
Most people fly into Islip Long Island (ISP) if they book a flight to Islip from Ontario. Long Island is conveniently located just 7.2 mi from Islip’s city center.
What are the most popular routes from Region of Ontario to Islip?
The most popular flight routes from Region of Ontario to Islip are Ottawa - Islip Long Island, Montreal Pierre Elliott Trudeau Intl - Islip Long Island and Toronto Pearson Intl - Islip Long Island.
Can I find deals for flights from Ontario to Islip that include hotel bookings?
Yes. In addition to deals on Ontario to Islip flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Ontario to Islip?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to Islip.
Can I find deals for business class flights from Ontario to Islip?
Yes. Cheapflights offers flight deals from Ontario 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 Region of Ontario to Islip?
Currently, January is the cheapest month in which you can book a flight from Region of Ontario to Islip (average of $108). Flying from Region of Ontario to Islip in November is currently the most expensive (average of $213). 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.

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$230+ Cheap flights from Ontario to Islip (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 10/13. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Ontario to Islip with Cheapflights

1. Tell us where you want to go

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Cheap flight deals from Ontario to Islip

Keep the following information in mind while searching for Ontario to Islip flight deals. Data was last updated September 11, 2025.

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Find flight deals from Ontario to Islip

Cheapest flights from Ontario to IslipExplore the most affordable flight options available from Ontario to Islip. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 11, 2025.

Explore the most affordable flight options available from Ontario to Islip. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 11, 2025.

Cheapflights Fare Finder

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

Best time to book a flight from Ontario to Islip

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

Cheapflights Insights

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

What is the cheapest month to book a flight from Region of Ontario to Islip?

Related info for your journey

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

What airport do you fly into for flights to Islip from Ontario?

What are the most popular routes from Region of Ontario to Islip?

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

How can I find direct flights from Ontario to Islip?

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

What is the cheapest month to book a flight from Region of Ontario to Islip?

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Cheapest flights from Ontario to Islip
Explore the most affordable flight options available from Ontario to Islip. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 11, 2025.