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San Juan

$183+ Cheap flights from Ontario (ONT) to San Juan

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 8/2. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SJU
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
1 adult, Economy
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Cheapflights Tip: The best prices from Ontario to San Juan are usually found in September or October, booked 24 days in advance, depart on a Tuesday or Monday and return on a Wednesday

Cheap flight deals from Ontario to San Juan

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to San Juan (PR1). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated June 12, 2025.

Round-trip from

$343
(Frontier)

One-way from

$183
(Delta)

Popular in

March

Cheapest in

September

Average price

$492
From Ontario to San Juan
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One-way flight from Ontario to San Juan
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Highest demand for flights based on searches. 1% potential increase in price ($11 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($13 potential savings vs. average RT price).
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Average for round-trip flights in June 2025
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Find flight deals from Ontario to San Juan

Cheapest flights from Ontario to San Juan
Explore the most affordable flight options available from Ontario to San Juan. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 12, 2025.

This Frontier deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/112:59 amONT - SJU
2 stops11h 38mFrontier
Mon 10/69:07 amSJU - ONT
2 stops14h 47mFrontier
Deal found 6/11$343
This Delta deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/165:05 pmONT - SJU
2 stops17h 18mDelta
Sat 9/2712:55 pmSJU - ONT
1 stop9h 47mDelta
Deal found 6/12$365
This JetBlue deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/710:56 pmONT - SJU
1 stop10h 44mJetBlue
Sat 9/1312:50 pmSJU - ONT
1 stop11h 39mJetBlue
Deal found 6/9$410
This United Airlines deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/186:04 amONT - SJU
1 stop11h 34mUnited Airlines
Mon 9/221:05 amSJU - ONT
2 stops14h 27mUnited Airlines
Deal found 6/11$413
This Southwest deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/25:45 amONT - SJU
2 stops11h 00mSouthwest
Wed 9/108:00 amSJU - ONT
2 stops14h 35mSouthwest
Deal found 6/12$451
This American Airlines deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/1012:46 pmONT - SJU
2 stops21h 00mAmerican Airlines
Thu 9/186:10 amSJU - ONT
2 stops19h 06mAmerican Airlines
Deal found 6/11$480

Cheapflights Fare Finder

Customize your flight search to find flights from Ontario to San Juan that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 12, 2025.
Use the filters below to find and compare flights from Ontario to San Juan that are best for you.

Fly from

Ontario

Fly to

San Juan

Route

Depart

Return

Price

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Wed 10/1

12:59 am-3:37 pm

2 stops11h 38m

San Juan Luis Munoz Marin Intl

Mon 10/6

9:07 am-8:54 pm

2 stops14h 47m

$343

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Tue 9/16

5:05 pm-1:23 pm

2 stops17h 18m

San Juan Luis Munoz Marin Intl

Sat 9/27

12:55 pm-7:42 pm

1 stop9h 47m

$365

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Sun 9/7

10:56 pm-2:53 pm

1 stop12h 57m

San Juan Luis Munoz Marin Intl

Sat 9/13

12:50 pm-9:29 pm

1 stop11h 39m

$410

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Thu 9/18

6:04 am-8:38 pm

1 stop11h 34m

San Juan Luis Munoz Marin Intl

Mon 9/22

1:05 am-12:32 pm

2 stops14h 27m

$413

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Tue 9/2

5:45 am-7:45 pm

2 stops11h 00m

San Juan Luis Munoz Marin Intl

Wed 9/10

8:00 am-7:35 pm

2 stops14h 35m

$451

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Wed 9/10

12:46 pm-12:46 pm

2 stops21h 00m

San Juan Luis Munoz Marin Intl

Thu 9/18

6:10 am-10:16 pm

2 stops19h 06m

$480

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Sat 8/2

7:05 am-8:39 pm

1 stop10h 34m

$183

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Mon 7/14

11:59 pm-3:12 pm

1 stop12h 13m

$205

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Mon 8/25

11:59 pm-3:00 pm

1 stop12h 01m

$219

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Thu 8/14

5:14 pm-4:00 pm

2 stops19h 46m

$220

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/10

Showing 1-10 of 15 results
1
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Best time to book a flight from Ontario to San Juan

Have a flexible travel schedule? Discover the best time to fly to San Juan 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 San Juan

How far ahead should I book a flight from Ontario to San Juan?

Use this chart to determine the optimal time to book a round-trip flight from Ontario to San Juan. Price data was last updated on June 9, 2025.

To ensure you get the cheapest price possible for a flight from Ontario to San Juan, you should look to book at least 24 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from Ontario to San Juan?

Currently, September is the cheapest month in which you can book a flight from Ontario to San Juan (average of $254). Flying from Ontario to San Juan in June is currently the most expensive (average of $339). 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.

What is the cheapest time of day to fly from ONT to SJU?

Find hourly flight availability from Ontario to San Juan. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated June 12, 2025.

One of the essential ways to save on airfare from Ontario to San Juan is to remain as flexible as possible. Flights that are in the afternoon tend to be the most expensive. A flight in the evening could potentially save you up to 27% on airfare.

What is the cheapest day to fly from Ontario to San Juan?

Use this chart to determine the cheapest time to fly round-trip from Ontario to San Juan. Price data was last updated on November 10, 2024.

Travelers seeking maximum savings on their Ontario to San Juan flight should consider departing on Tuesday evenings when fares are most often at their lowest. Sunday mornings flights should be avoided if possible as fares are typically the most expensive at this time.

Rainfall in San Juan by month

Plan your trip to San Juan by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in San Juan ranges from 2.2 - 6.1 inches per month. November is typically the wettest month, when rainfall can reach 6.1 in. February is typically the driest time to visit San Juan when rainfall is around 2.2 in.

Temperature in San Juan by month

Plan your trip to San Juan by taking into account the average temperature totals by month.

If weather is an important factor for your trip to San Juan, use this chart to help with planning. For those seeking warmer temperatures, June is the ideal time of year to visit, when temperatures reach an average of 82.4 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 77.0 F).

Reviews of airlines servicing San Juan

Get insights into the airlines that provide service to San Juan. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to San Juan. Reviews last updated June 12, 2025.
Read through reviews of airlines operating flights from Ontario to San Juan, such as Alaska Airlines, Southwest and Delta. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Southwest
8.0
Very good
4,287 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Delta
8.0
Very good
7,946 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
United Airlines
7.4
Good
8,790 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
JetBlue
7.3
Good
2,925 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Related info for your journey

Find useful and relevant information for your journey from Ontario to San Juan. 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 from for flights from Ontario to San Juan?

    If you book a flight to San Juan from Ontario, you will be flying from Ontario, which is the city’s only airport. Ontario (ONT) is located 3.1 mi from the center of Ontario. There are 0 flights from Ontario to San Juan per day from 5 different airlines.

  • What are the cheapest airlines flying from Ontario to San Juan round-trip?

    Frontier, at $343, was found to be the cheapest airline from Ontario to San Juan.Alternate airlines to your destination round-trip include Delta and JetBlue. Frontier is currently priced 38% below the average price you’ll pay for this route.

  • What are the cheapest airlines to fly from Ontario to San Juan one-way?

    $183 is the cheapest one-way deal found within the past few days, from Delta. You may also be able to find cheap deals on JetBlue and American Airlines, with prices starting from $205 and $219, respectively.

  • Can I find deals for flights from Ontario to San Juan that include hotel bookings?

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

  • How can I find direct flights from Ontario to San Juan?

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

  • Can I find deals for business class flights from Ontario to San Juan?

    Yes. Cheapflights offers flight deals from Ontario to San Juan 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 Ontario to San Juan?

    Currently, September is the cheapest month in which you can book a flight from Ontario to San Juan (average of $254). Flying from Ontario to San Juan in June is currently the most expensive (average of $339). 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

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Top 5 airlines flying from Ontario to San Juan

Discover the top 5 airlines that operate flights from Ontario to San Juan. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$73Average$331FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$322Average$584FlexibilityNo cancel feeOn-time69%
DeltaCheapest$334Average$502FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$353Average$608FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$409Average$570FlexibilityNo cancel feeOn-time63%

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