How long is the flight from Seattle to Cardiff?

Departing from Seattle to Cardiff will take you 35h. There are 4709 mi between Seattle and Cardiff.

What is the cheapest month to book a flight from Seattle to Cardiff?

Currently, February is the cheapest month in which you can book a flight from Seattle to Cardiff (average of $773). Flying from Seattle to Cardiff in June is currently the most expensive (average of $1,622). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest day to fly from Seattle to Cardiff?

Travelers seeking maximum savings on their Seattle to Cardiff flight should consider departing on Sunday afternoons when fares are most often at their lowest. Monday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

In terms of precipitation, rainfall in Cardiff ranges from 2.0 - 3.5 inches per month. January is typically the wettest month, when rainfall can reach 3.5 in. April is typically the driest time to visit Cardiff when rainfall is around 2.0 in.

If weather is an important factor for your trip to Cardiff, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 64.4 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 39.2 F).

What is the cheapest day to fly round-trip from Seattle to Cardiff?

Users have found that flying from Seattle to Cardiff on a Sunday typically leans towards higher prices. However, this doesn’t mean you still can’t find a deal. Flexibility with other aspects of your flight can still land a great price for your trip.

What is the cheapest month to fly from Seattle to Cardiff?

January can be a great time to fly to Cardiff from Seattle with a flight ticket averaging about $1,155. Cheapflights users have found deals in the month of January for as cheap as $878. The most expensive prices can be found in the month of June.

Can I find deals for flights from Seattle to Cardiff that include hotel bookings?

Yes. In addition to deals on Seattle to Cardiff flights, Cheapflights offers vacation packages that include both flights and hotel.

How can I find direct flights from Seattle to Cardiff?

After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Cardiff.

Can I find deals for business class flights from Seattle to Cardiff?

Yes. Cheapflights offers flight deals from Seattle to Cardiff by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

$10,179+ Cheap Flights from Seattle to Cardiff

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Cheap flight deals from Seattle to Cardiff

Round-trip from	$10,179 (KLM)
Popular in	June
Cheapest in	January
Average price	$1,233

From Seattle/Tacoma Intl to Cardiff Wales

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Highest demand for flights based on searches. 18% potential increase in price ($266 potential increase over avg. RT price).

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Cheapest flight prices on average. 5% potential price decrease ($60 potential savings vs. average RT price).

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Average for round-trip flights in September 2025

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Cheapest flights from Seattle to Cardiff
Explore the most affordable flight options available from Seattle to Cardiff. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 15, 2025.

Thu 9/252:10 pmSEA - CWL

1 stop35h 00mKLM

Tue 9/309:50 amCWL - SEA

2 stops17h 10mKLM

Deal found 9/14

$10,179

Best flights from Seattle to Cardiff
Discover carefully curated flight deals from Seattle to Cardiff that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 15, 2025.

Thu 9/252:10 pmSEA - CWL

1 stop35h 00mKLM

Tue 9/309:50 amCWL - SEA

2 stops17h 10mKLM

Deal found 9/14

$10,179

Last-minute flights from Seattle to Cardiff
Discover last-minute flight deals from Seattle to Cardiff. Data last updated September 15, 2025 and is based on user searches.

Thu 9/252:10 pmSEA - CWL

1 stop35h 00mKLM

Tue 9/309:50 amCWL - SEA

2 stops17h 10mKLM

Deal found 9/14

$10,179

Fly from

Fly to

Route

Depart

Return

Price

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 9/25

2:10 pm-9:10 am

1 stop35h 00m

Cardiff Wales

Tue 9/30

9:50 am-7:00 pm

2 stops17h 10m

$10,179

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/14

Best time to book a flight from Seattle to Cardiff

Have a flexible travel schedule? Discover the best time to fly to Cardiff from Seattle with our price prediction graph.

Estimated round-trip price

Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Seattle to Cardiff

What is the cheapest time of day to fly from SEA to CWL?

When flying from Seattle to Cardiff, the time of day you fly usually plays a role in the price. Save by searching for a flight in the morning, which can drop the price by up to 17% versus a flight at noon.

Related info for your journey

How long is the flight from Seattle to Cardiff?
Departing from Seattle to Cardiff will take you 35h. There are 4709 mi between Seattle and Cardiff.
Can I find deals for flights from Seattle to Cardiff that include hotel bookings?
Yes. In addition to deals on Seattle to Cardiff flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Seattle to Cardiff?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Cardiff.
Can I find deals for business class flights from Seattle to Cardiff?
Yes. Cheapflights offers flight deals from Seattle to Cardiff by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.
What is the cheapest month to book a flight from Seattle to Cardiff?
Currently, February is the cheapest month in which you can book a flight from Seattle to Cardiff (average of $773). Flying from Seattle to Cardiff in June is currently the most expensive (average of $1,622). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

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$10,179+ Cheap flights from Seattle (SEA) to Cardiff (CWL)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 9/25. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Seattle to Cardiff with Cheapflights

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2. Select your favorite providers

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Cheap flight deals from Seattle to Cardiff

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Find flight deals from Seattle to Cardiff

Cheapest flights from Seattle to CardiffExplore the most affordable flight options available from Seattle to Cardiff. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 15, 2025.

Explore the most affordable flight options available from Seattle to Cardiff. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 15, 2025.

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Use the filters below to find and compare flights from Seattle to Cardiff that are best for you.

Best time to book a flight from Seattle to Cardiff

Have a flexible travel schedule? Discover the best time to fly to Cardiff from Seattle with our price prediction graph.

Cheapflights Insights

Everything you need to know about your flight from Seattle to Cardiff

What is the cheapest time of day to fly from SEA to CWL?

Related info for your journey

Find useful and relevant information for your journey from Seattle to Cardiff. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

How long is the flight from Seattle to Cardiff?

Can I find deals for flights from Seattle to Cardiff that include hotel bookings?

How can I find direct flights from Seattle to Cardiff?

Can I find deals for business class flights from Seattle to Cardiff?

What is the cheapest month to book a flight from Seattle to Cardiff?

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Cheapest flights from Seattle to Cardiff
Explore the most affordable flight options available from Seattle to Cardiff. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 15, 2025.