$167 Cheap Southwest Airlines flights Boston (BOS) to San Juan (SJU)

You'll find budget-friendly return Southwest Airlines flights from $328 from BOS to SJU by filtering your results from "Price (lowest to highest)" on Expedia. Or look for options from $167 for a one-way trip.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

Start your search for Southwest Airlines flights from BOS to SJU about one month before you want to go. The cheapest time to book an international flight is generally 18 to 29 days ahead of your travel date when you can save 17% versus booking four to five months in advance. Regardless of itinerary or fare class, the best day to book international airfare is usually Sunday. Friday can be the most expensive. Passengers who book on a Sunday can save 17% on average compared to those who book on a Friday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.

Filter your results by "Morning" and "Early Morning" to browse the earliest departures from BOS to SJU. Leaving early means flight cancellations are less likely.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.