$373 Find Cheap Flights from Porto to Washington

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Porto to Washington departing on 12/15. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy

KAYAK searches hundreds of travel sites at once for deals on flights to Washington

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Porto to Washington, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Porto to Washington, as well as popular online travel agencies
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Flight Deals

Cheap Flights from Porto to Washington

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Seattle
Seattle1 stop$775
Seattle
Seattle1 stop$775

Book Cheap Porto to Washington Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Porto to Washington that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Porto to Washington

Fri, Sep 26 - Tue, Sep 30
Delta Logo
6:40 am - 4:05 pmOPO-SEA
17h 25m1 stop
Delta Logo
1:30 pm - 3:30 pmSEA-OPO
18h 00m1 stop
$775Delta
Find Deal
Fri, Oct 31 - Mon, Nov 10
Delta Logo
6:30 am - 8:19 pmOPO-SEA
20h 49m2 stops
Delta Logo
7:30 am - 10:15 amSEA-OPO
18h 45m2 stops
$780Delta
Find Deal
Wed, Oct 29 - Wed, Nov 5
KLM Logo
11:15 am - 12:45 pmOPO-SEA
32h 30m1 stop
KLM Logo
9:29 am - 10:30 amSEA-OPO
17h 01m2 stops
$784KLM
Find Deal
Fri, Oct 31 - Mon, Nov 10
KLM Logo
6:30 am - 8:19 pmOPO-SEA
20h 49m2 stops
KLM Logo
2:05 pm - 10:30 amSEA-OPO
36h 25m1 stop
$785KLM
Find Deal
Fri, Oct 31 - Mon, Nov 10
 Logo
12:00 pm - 4:40 pmOPO-SEA
35h 40m3 stops
 Logo
5:40 pm - 8:10 amSEA-OPO
30h 30m3 stops
Mon, Oct 13 - Mon, Oct 20
Lufthansa Logo
6:00 am - 11:55 amOPO-SEA
13h 55m1 stop
Lufthansa Logo
7:00 am - 10:20 amSEA-OPO
19h 20m2 stops
$832Lufthansa
Find Deal
Mon, Oct 13 - Mon, Oct 20
Lufthansa Logo
6:00 am - 11:55 amOPO-SEA
13h 55m1 stop
Lufthansa Logo
2:20 pm - 3:45 pmSEA-OPO
17h 25m1 stop
$835Lufthansa
Find Deal
Mon, Oct 13 - Mon, Oct 20
 Logo
7:00 am - 8:40 pmOPO-SEA
21h 40m2 stops
 Logo
3:45 pm - 8:00 amSEA-OPO
32h 15m3 stops
Mon, Oct 13 - Mon, Oct 20
United Airlines Logo
12:10 pm - 6:49 pmOPO-SEA
38h 39m2 stops
United Airlines Logo
8:00 am - 9:45 amSEA-OPO
17h 45m2 stops
$895United Airlines
Find Deal
Tue, Nov 18 - Mon, Dec 1
United Airlines Logo
12:35 pm - 12:59 amOPO-SEA
20h 24m2 stops
United Airlines Logo
8:36 am - 11:05 amSEA-OPO
18h 29m3 stops
$1,360United Airlines
Find Deal
Booking Insights

KAYAK's insights & trends for Porto to Washington flights

Get data-powered insights and trends into flights from Porto to Washington to help you find the cheapest flights, the best time to fly and much more.

What’s the cheapest day of the week to fly from Porto to Washington?

The average price of all round-trip flights from Porto to Washington clicked on KAYAK for each day over the last 12 months.

For Porto to Washington, Monday is the cheapest day to fly on average and Saturday is the most expensive. Flying from Washington back to Porto, the best deals are generally found on Tuesday, with Thursday being the most expensive.

Good to know

Low seasonOctober
Cheapest flight$373
Best time to beat the crowds with an average 63% drop in price.
Most popular time to fly with an average 20% increase in price.
Flight from Porto to Seattle

FAQs - booking Washington flights

  • How does KAYAK find such low prices on flights from Porto to Washington?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Porto to Washington.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Porto to Washington?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Porto to Washington is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Porto to Washington?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly from Porto to Washington with an airline and back with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Porto to Washington?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying from Porto to Washington up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • What is the cheapest time of day to fly to Washington?

    The cheapest time of day to fly to Washington is generally in the evening, when round-trip flights cost $792 on average. Morning departures are around 20% more expensive than evening flights, on average. The most expensive time of day to fly to Washington is generally in the morning, which is peak travel time and where the average cost of a ticket is $934.

Reviews of the top airline flying from Porto to Washington

 
See real verified KAYAK customer reviews for airlines flying from Porto to Washington. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Porto to Washington? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.8
KLMOverall score based on 1385 reviews
8.4Crew
7.2Entertainment
7.3Food
7.8Boarding
7.7Comfort
Airline reviews

First of all we couldn’t check in online, then we learn at the airport we were on stand by for KLM’s mistake of overbooking. The seats were not comfy at all. Our luggage got lost.

2.0 MediocreAnonymous, Aug 2025CTA - AMS
Read more KLM reviews

First of all we couldn’t check in online, then we learn at the airport we were on stand by for KLM’s mistake of overbooking. The seats were not comfy at all. Our luggage got lost.

Ad experience - been flying many years with them but they are losing out to other carriers with their service and bagage / seating policy. My 2 12-yo kids were not placed with the parent. Absurdity.

Short flight so it was okay. Nice crew, all very pleasant and professional. We were near the back in row 27 so just as we got our drinks, we started our descent so had to drink very quickly!

KLM remains a quality flag carrier airline which maintains its standards whilst all their competitors are lowering theirs.

The baggage drop-off in Stuttgart is bad: after online check-in you cannot use the automated baggage drop off as indicated on the website. You can use the terminals but have to cue to 1 of three open and slowly working counters to drop the bags. took about 45 minutes wait time.

Our first flight was delayed so we missed our connecting flight. However it was easy to book a later flight on their app.

The service was great. However the lounge only gets passing grade

Cabin crew professional, polite and friendly, boarding was seemless, but come on KLM surely you can do better than a pack of cheesy biscuits as an inflight snack

Cabin crew were excellent, very proffesional, polite and friendly, in flight snack was underwhelming, a packet of cheese biscuits, im sure KLM could run to a sandwich!

Legroom not all it could be, especially when the seat in front is reclined. Otherwise it was good, food and beverage were nice.

Everything you need to know for your flight from Porto to Washington

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