Cheapest return flights from Washington to Porto in August from $523

Best time to book flights for Washington (IAD) to Porto (OPO) flights at AirHint

AirHint found the following cheapest return flights from Washington (IAD) to Porto (OPO) in August 2025 (see full year).

Return flights

12 Aug - 19 Aug SWISS
13 Aug - 20 Aug TAP
19 Aug - 26 Aug TAP
20 Aug - 27 Aug TAP
14 Aug - 21 Aug TAP
26 Aug - 02 Sep TAP
18 Aug - 25 Aug TAP
06 Aug - 13 Aug Iberia
15 Aug - 22 Aug TAP
21 Aug - 25 Aug TAP
05 Aug - 12 Aug United
25 Aug - 01 Sep KLM
31 Aug - 07 Sep TAP

Also check the deals for one-way flights from Washington to Porto in August.

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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