Cheapest one-way flights from Seattle to Helsinki in September from 441€

AirHint found the following cheapest one-way flights from Seattle (SEA) to Helsinki (HEL) in September 2025 (see full year).

One-Way flights

21 Sep Turkish Airlines
22 Sep Finnair
23 Sep Finnair
24 Sep Finnair
30 Sep Finnair
28 Sep Finnair
25 Sep Finnair
27 Sep Finnair
02 Sep Finnair
09 Sep Finnair

Also check the deals for return flights from Seattle to Helsinki in September.

Skyscanner

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.

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