Cheapest return SEA–SJO flights, September

AirHint found the following cheapest return flights from Seattle (SEA) to San Jose (SJO) in September 2026 (see full year).

Return flights

06 Sep - 10 Sep Southwest Airlines
11 Sep - 19 Sep Alaska Airlines
03 Sep - 07 Sep Southwest Airlines

Also check the deals for one-way flights from Seattle to San Jose in September.

Powered by

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

Book a cheap hotel in San Jose

Cheap car rent in San Jose

Feel free to contact us with any feedback or request another flight research.