What are the cheapest airlines flying from Seattle to Cardiff round-trip?

Cheapflights users have booked flights from Seattle to Cardiff round-trip from $879. Other airlines that can offer you cheap pricing are Delta, from $981, and KLM, from $1,014. These flights start at 23% lower than the current average price 3 months from now.

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 $1,152. 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.

$579+ Flights from Seattle to Cardiff

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Cheap flight deals from Seattle to Cardiff

Round-trip from	$579 (Kiwi.com)
Popular in	June
Cheapest in	January
Average price	$1,649

From Seattle/Tacoma Intl to Cardiff Wales

Search Deals

Highest demand for flights based on searches. 21% potential increase in price ($319 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 4% potential price decrease ($55 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in July 2025

Search Deals

Find flight deals from Seattle to Cardiff

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 July 3, 2025.

Mon 8/257:35 pmSEA - CWL

1 stop12h 20mMultiple Airlines

Mon 9/11:10 pmCWL - SEA

1 stop12h 40mMultiple Airlines

Deal found 7/1

$579

Mon 8/255:30 amSEA - CWL

2 stops43h 45mVirgin Atlantic

Mon 9/19:50 amCWL - SEA

2 stops55h 55mVirgin Atlantic

Deal found 7/1

$879

Fri 8/159:40 amSEA - CWL

2 stops23h 25mDelta

Fri 8/229:50 amCWL - SEA

1 stop14h 05mDelta

Deal found 6/30

$981

Fri 8/155:40 pmSEA - CWL

1 stop31h 35mKLM

Fri 8/229:50 amCWL - SEA

1 stop14h 05mKLM

Deal found 6/30

$1,014

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 July 3, 2025.

Mon 8/257:35 pmSEA - CWL

1 stop12h 20mMultiple Airlines

Mon 9/11:10 pmCWL - SEA

1 stop12h 40mMultiple Airlines

Deal found 7/1

$579

Mon 8/255:30 amSEA - CWL

2 stops43h 45mVirgin Atlantic

Mon 9/19:50 amCWL - SEA

2 stops55h 55mVirgin Atlantic

Deal found 7/1

$879

Fri 8/159:40 amSEA - CWL

2 stops23h 25mDelta

Fri 8/229:50 amCWL - SEA

1 stop14h 05mDelta

Deal found 6/30

$981

Fri 8/155:40 pmSEA - CWL

1 stop31h 35mKLM

Fri 8/229:50 amCWL - SEA

1 stop14h 05mKLM

Deal found 6/30

$1,014

Last-minute flights from Seattle to Cardiff
Discover last-minute flight deals from Seattle to Cardiff. Data last updated July 3, 2025 and is based on user searches.

Fri 8/159:40 amSEA - CWL

2 stops23h 25mDelta

Fri 8/229:50 amCWL - SEA

1 stop14h 05mDelta

Deal found 6/30

$981

Fri 8/155:40 pmSEA - CWL

1 stop31h 35mKLM

Fri 8/229:50 amCWL - SEA

1 stop14h 05mKLM

Deal found 6/30

$1,014

Mon 8/257:35 pmSEA - CWL

1 stop12h 20mMultiple Airlines

Mon 9/11:10 pmCWL - SEA

1 stop12h 40mMultiple Airlines

Deal found 7/1

$579

Mon 8/255:30 amSEA - CWL

2 stops43h 45mVirgin Atlantic

Mon 9/19:50 amCWL - SEA

2 stops55h 55mVirgin Atlantic

Deal found 7/1

$879

One-way flights from Seattle to Cardiff
Search for one-way flight options from Seattle to Cardiff. Find affordable one-way fares based on user searches. Data last updated July 3, 2025.

Thu 8/75:05 pmSEA - CWL

3 stops37h 15mMultiple Airlines

Deal found 7/2

$1,069

Thu 8/72:10 pmSEA - CWL

1 stop18h 35mKLM

Deal found 7/2

$1,380

Cheapflights Fare Finder

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

Fly from

Fly to

Route

Depart

Return

Price

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Mon 8/25

7:35 pm-3:55 pm

1 stop12h 20m

Cardiff Wales

Mon 9/1

1:10 pm-5:50 pm

1 stop12h 40m

$579

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Mon 8/25

5:30 am-9:15 am

2 stops43h 45m

Cardiff Wales

Mon 9/1

9:50 am-9:45 am

2 stops55h 55m

$879

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Fri 8/15

9:40 am-5:05 pm

2 stops23h 25m

Cardiff Wales

Fri 8/22

9:50 am-3:55 pm

1 stop14h 05m

$981

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Fri 8/15

5:40 pm-9:15 am

1 stop31h 35m

Cardiff Wales

Fri 8/22

9:50 am-3:55 pm

1 stop14h 05m

$1,014

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 8/7

5:05 pm-2:20 pm

3 stops37h 15m

$1,069

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 8/7

2:10 pm-4:45 pm

1 stop18h 35m

$1,380

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/2

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.

Reviews of airlines servicing Cardiff

Read reviews from past customers who have flown Delta, KLM, and Virgin Atlantic from Seattle to Cardiff. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.

Delta

8.0

Very good

7,982 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Delta

8.0

Very good

7,982 reviews

Delta

8.0

Very good

7,982 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

KLM

7.8

Good

1,367 reviews

Delta

8.0

Very good

7,982 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Virgin Atlantic

7.4

Good

654 reviews

Delta

8.0

Very good

7,982 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Related info for your journey

What are the cheapest airlines flying from Seattle to Cardiff round-trip?
Cheapflights users have booked flights from Seattle to Cardiff round-trip from $879. Other airlines that can offer you cheap pricing are Delta, from $981, and KLM, from $1,014. These flights start at 23% lower than the current average price 3 months from now.
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.

See more FAQs

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Alternative routes for Seattle to Cardiff

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Top airline flying from Seattle to Cardiff

Airline	Cheapest	Average	Flexibility	On-time
KLM	Cheapest$760	Average$1,132	FlexibilityNo cancel fee	On-time75%

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$579+ 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 8/25. 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

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheap flight deals from Seattle to Cardiff

Round-trip from

Popular in

Cheapest in

Average price

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 July 3, 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 July 3, 2025.

Cheapflights Fare Finder

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?

Find hourly flight availability from Seattle to Cardiff. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated July 3, 2025.

Reviews of airlines servicing Cardiff

Read reviews from past customers who have flown Delta, KLM, and Virgin Atlantic from Seattle to Cardiff. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.

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.

What are the cheapest airlines flying from Seattle to Cardiff round-trip?

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?

Traveling to a place near Seattle?

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Alternative routes for Seattle to Cardiff

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Top airline flying from Seattle to Cardiff

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Travel Smart

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 July 3, 2025.