Cheap Flights from Seattle (SEA) to Cascais (CAT)

Popular airlines from Seattle-Tacoma International Airport (SEA) to Cascais (CAT)

Alternative airports near Cascais

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Humberto Delgado LIS. Cheapest option available. Average driving time to city center is 24 minutes. Flights from $2,601
LIS
Humberto Delgado
Cheapest
Average driving time to city center24 min
Flights from $2,601
Flights from Seattle (SEA) to Cascais (CAT)
Origin airport
Seattle - Tacoma Intl.
Destination airport
Cascais
Distance
5197 mi

Seattle to Cascais Flights

The cheapest times to fly from Seattle to Cascais

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Seattle to Cascais are during the month of . You can find some of the cheapest flights from Seattle to Cascais with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Seattle to Cascais

Sunday is one of the best days to book for cheap flights from Seattle to Cascais: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Seattle to Cascais

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Seattle to Cascais in 2026. You can also book with separate airlines for your outbound and return journeys, from one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Seattle to Cascais flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Seattle to Cascais airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Seattle - Tacoma Intl. Airport (SEA) to Cascais Airport (CAT) cost?
Lock in a cheap one-way flight or cheap return flight from Seattle - Tacoma Intl. Airport (SEA) to Cascais Airport (CAT) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight deals on this route.
What is the cheapest month to fly from Seattle - Tacoma Intl. Airport (SEA) to Cascais Airport (CAT)?
The cheapest month to fly from SEA to CAT is , when there's less demand. Off-peak season is generally when airlines offer better prices between these airports.
What is the cheapest airline that flies from Seattle - Tacoma Intl. Airport (SEA) to Cascais Airport (CAT)?
Expedia's filter tool lets you easily compare different airlines, travel time and fares all in one place. Customize the search to your preferences, then sort by "Price (lowest to highest)" to see which carrier offers the cheapest SEA to CAT flight.
How many flights per day from Seattle - Tacoma Intl. Airport (SEA) to Cascais Airport (CAT)?
There are no daily nonstop flights from Seattle - Tacoma Intl. Airport (SEA) to Cascais Airport (CAT). But you can choose flights with layovers. Filter your search on Expedia to include one or more stops, and you'll be cruising above the clouds in no time at all.
What day of the week has the most flights from SEA to CAT?
You'll usually find Tuesday the quietest day for flights, while Fridays are often the busiest.* However this can vary from season to season and during peak travel times or public holidays.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Seattle - Tacoma Intl. Airport (SEA) to Cascais Airport (CAT)?
Book a flight from Seattle - Tacoma Intl. Airport (SEA) to Cascais Airport (CAT) that takes off before 3 PM to reduce the risk of cancellations and delays. Later departures are on average 22% more likely to be canceled.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from Seattle - Tacoma Intl. Airport (SEA) to Cascais Airport (CAT) last-minute?
Waiting until just before your departure to book a ticket from SEA to CAT often results in higher prices. While you may come across some last-minute deals, they aren't always guaranteed. Keep your travel plans flexible for the best chance of snagging a bargain.
Is it cheaper to book a SEA to CAT flight and hotel package?
You can save money by booking a SEA to CAT flight and hotel package compared to booking separately. In fact, you could save hundreds of dollars by bundling with Expedia. And it's easy to manage it all in one convenient place. After selecting your preferred flights and accommodations, consider adding extras like car rentals, tours and activities.
Can I cancel or change the date of my flight from Seattle - Tacoma Intl. Airport (SEA) to Cascais Airport (CAT)?
If you booked your SEA to CAT flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the fare type you purchased, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, go to our Customer Service portal if you want more information.

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*Available to One Key members.