$323 Cheap United flights San Juan (SJU) to Watertown (ATY)

Finding cheap one-way United Airlines flights from SJU to ATY from $323 on Expedia is easy — just filter by "Price (lowest to highest)." Or check out our affordable return fares from $604 for your next adventure.**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.

Check for United Airlines flights from SJU to ATY about one month before you want to leave. The most affordable time to reserve 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. No matter your ticket type or itinerary, the best day of the week to book international airfare is usually Sunday. Friday can be the most expensive. Travelers 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 SJU to ATY. Heading off 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.

Journey from SJU to ATY with United Airlines and enjoy a host of benefits including a rewarding loyalty program. When booking through Expedia as a United Mileage Plus and One Key™ member, you could also earn OneKeyCash™* to spend on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.