$1,366 Cheap Delta flights Porto (OPO) to San Diego (SAN)

Set the "Price (lowest to highest)" filter on Expedia to search for cheap Delta Air Lines round-trip flights from $915 from OPO to SAN. Affordable one-way fares from $1,366 are also on offer.**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.

Snagging the best Delta Air Lines deals from OPO to SAN often comes down to booking at the right moment. You can save 17% on international flights when you book 18 to 29 days before takeoff instead of four to five months ahead. What's more, you can pocket 17% on average by buying your fare on a Sunday compared to a Friday, which is usually the most expensive day to book.* It's a good idea to start checking out flights about one month before your travel dates.*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.

To find the earliest departure from OPO to SAN with Delta Air Lines, filter your results by "Early Morning" and "Morning." Booking an early flight usually means you'll experience fewer cancellations.**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.

Offering an excellent in-flight experience and a rewarding loyalty program, Delta Air Lines is a popular option for many travelers heading from OPO to SAN. Plus, if you're a Delta SkyMiles and One Key™ member booking with Expedia, you could earn OneKeyCash™* on eligible flights on top of your airline miles, which can be spent on future travel.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.