AirHint found the following cheapest return flights from Seattle (SEA) to Mexico City (MEX) in August 2025 (see full year).

Return flights

17 Aug - 24 Aug	Hawaiian Airlines
15 Aug - 22 Aug	Volaris
21 Aug - 29 Aug	Alaska Airlines
11 Aug - 15 Aug	Hawaiian Airlines
16 Aug - 23 Aug	Volaris
28 Aug - 01 Sep	Hawaiian Airlines
28 Aug - 31 Aug	Frontier Airlines
10 Aug - 14 Aug	Spirit Airlines
14 Aug - 17 Aug	Hawaiian Airlines
18 Aug - 27 Aug	Hawaiian Airlines
09 Aug - 14 Aug	Hawaiian Airlines
28 Aug - 05 Sep	Air Canada

Also check the deals for one-way flights from Seattle to Mexico City in August.

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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Cheapest return flights from Seattle to Mexico City in August from 309€

Return flights