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$923+ 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 4/23. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — CWL
Apr 2 — Apr 91
Wed 4/2
Wed 4/9
1 adult, Economy
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Cheap flight deals from Seattle to Cardiff

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Cardiff (CWL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated March 28, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$923
(KLM)

Popular in

June

Cheapest in

April

Average price

$941
Provider with most accurate pricing for Seattle/Tacoma Intl-Cardiff Wales flight deals.
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Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Cardiff Wales flights.
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From Seattle/Tacoma Intl to Cardiff Wales
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Highest demand for flights based on searches. 20% potential increase in price ($284 potential increase over avg. RT price).
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Cheapest flight prices on average. 6% potential price decrease ($63 potential savings vs. average RT price).
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Average for round-trip flights in March 2025
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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 March 28, 2025.

This KLM deal was found by Cheapflights users on 3/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/206:10 pmSEA - CWL
1 stop14h 35mKLM
Wed 5/215:15 pmCWL - SEA
1 stop26h 25mKLM
Deal found 3/27$986
This Delta deal was found by Cheapflights users on 3/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/206:20 amSEA - CWL
2 stops18h 55mDelta
Wed 5/219:50 amCWL - SEA
1 stop14h 07mDelta
Deal found 3/27$991
This Air France deal was found by Cheapflights users on 3/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/118:35 amSEA - CWL
2 stops16h 40mMultiple Airlines
Sun 5/189:50 amCWL - SEA
2 stops18h 33mMultiple Airlines
Deal found 3/26$1,103

Cheapflights Fare Finder

Customize your flight search to find flights from Seattle to Cardiff that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated March 28, 2025.
Use the filters below to find and compare flights from Seattle to Cardiff that are best for you.

Fly from

Seattle

Fly to

Cardiff

Route

Depart

Return

Price

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Sun 4/20

6:10 pm-4:45 pm

1 stop14h 35m

Cardiff Wales

Wed 5/21

5:15 pm-11:40 am

1 stop26h 25m

$986

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Sun 4/20

6:20 am-9:15 am

2 stops18h 55m

Cardiff Wales

Wed 5/21

9:50 am-3:57 pm

1 stop14h 07m

$991

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Sun 5/11

8:35 am-9:15 am

2 stops16h 40m

Cardiff Wales

Sun 5/18

9:50 am-8:23 pm

2 stops18h 33m

$1,103

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/27

Compare providers for flights from Seattle to Cardiff

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Seattle to Cardiff in March.
ProviderPrice AccuracyTrust Score*
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Seattle-Cardiff flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-Cardiff flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-Cardiff flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-Cardiff flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Seattle-Cardiff flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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?

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 March 28, 2025.

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.

Rainfall in Cardiff by month

Plan your trip to Cardiff by taking into account the average rainfall totals by month.

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.

Temperature in Cardiff by month

Plan your trip to Cardiff by taking into account the average temperature totals by month.

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).

Reviews of airlines servicing Cardiff

Get insights into the airlines that provide service to Cardiff. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Cardiff. Reviews last updated March 28, 2025.
Delta
8.0
Very good
7,897 reviews

Boarding

8.2

Entertainment

7.9

Crew

8.5

Food

7.3

Comfort

8.0

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
Delta
8.0
Very good
7,897 reviews
Delta
8.0
Very good
7,897 reviews

Boarding

8.2

Entertainment

7.9

Crew

8.5

Food

7.3

Comfort

8.0

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
KLM
7.8
Good
1,321 reviews
Delta
8.0
Very good
7,897 reviews

Boarding

8.2

Entertainment

7.9

Crew

8.5

Food

7.3

Comfort

8.0

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

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?

    Cheapflights users have booked flights from Seattle to Cardiff round-trip from $923. Another airline that can offer you cheap pricing is Delta. These flights start at 15% 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.

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Top airline flying from Seattle to Cardiff

Discover the top airline that operate flights from Seattle to Cardiff. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated March 28, 2025.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest$760Average$1,202FlexibilityNo cancel feeOn-time75%
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