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$526+ Cheap flights from Basel EuroAirport Swiss (BSL) to Seattle (SEA)

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 9/12. Fares are subject to change and may not be available on all flights or dates of travel.
BSL — SEA
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
1 adult, Economy
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Cheap flight deals from Basel to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from Basel (BSL) to Seattle (SEA). 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 June 12, 2025.

Round-trip from

$526
(Gotogate)

Popular in

July

Cheapest in

November

Average price

$720
From Basel EuroAirport Swiss to Seattle/Tacoma Intl
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Highest demand for flights based on searches. 23% potential increase in price ($208 potential increase over avg. RT price).
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Cheapest flight prices on average. 9% potential price decrease ($57 potential savings vs. average RT price).
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Average for round-trip flights in June 2025
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Find flight deals from Basel to Seattle

Cheapest flights from Basel to Seattle
Explore the most affordable flight options available from Basel to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 12, 2025.

This Gotogate deal was found by Cheapflights users on 6/10. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/126:00 amBSL - SEA
1 stop14h 35mBritish Airways
Thu 10/21:30 pmSEA - BSL
1 stop12h 25mBritish Airways
Deal found 6/10$526
This American Airlines deal was found by Cheapflights users on 6/11. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/236:35 amBSL - SEA
1 stop14h 00mAmerican Airlines
Wed 9/241:30 pmSEA - BSL
1 stop24h 10mAmerican Airlines
Deal found 6/11$529
This Billigflug deal was found by Cheapflights users on 6/10. 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 Billigflug is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/26:10 amBSL - SEA
2 stops23h 02mMultiple Airlines
Sat 10/181:35 pmSEA - BSL
1 stop19h 50mMultiple Airlines
Deal found 6/10$536
This Delta deal was found by Cheapflights users on 6/12. 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.
Fri 9/196:15 amBSL - SEA
2 stops19h 43mDelta
Sun 9/211:30 pmSEA - BSL
1 stop14h 40mDelta
Deal found 6/12$568
This United Airlines deal was found by Cheapflights users on 6/12. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/89:45 amBSL - SEA
1 stop16h 14mUnited Airlines
Sun 12/143:10 pmSEA - BSL
1 stop12h 15mUnited Airlines
Deal found 6/12$670
This Lufthansa deal was found by Cheapflights users on 6/10. 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 Lufthansa is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/186:05 amBSL - SEA
1 stop14h 50mLufthansa
Wed 7/306:50 pmSEA - BSL
1 stop15h 45mLufthansa
Deal found 6/10$680
This KLM deal was found by Cheapflights users on 6/11. 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 7/66:25 pmBSL - SEA
1 stop30h 25mKLM
Mon 8/115:40 pmSEA - BSL
1 stop30h 55mKLM
Deal found 6/11$888
This Turkish Airlines deal was found by Cheapflights users on 6/10. 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 Turkish Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/126:55 pmBSL - SEA
1 stop31h 20mTurkish Airlines
Thu 10/27:10 pmSEA - BSL
1 stop37h 50mTurkish Airlines
Deal found 6/10$4,403

Cheapflights Fare Finder

Customize your flight search to find flights from Basel to Seattle 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 June 12, 2025.
Use the filters below to find and compare flights from Basel EuroAirport Swiss to Seattle that are best for you.

Fly from

Basel

Fly to

Seattle

Route

Depart

Return

Price

BaselSeattle

BSL - SEA

BSLSEA

Basel EuroAirport Swiss

Fri 9/12

6:00 am-11:35 am

1 stop14h 35m

Seattle/Tacoma Intl

Thu 10/2

1:30 pm-10:55 am

1 stop12h 25m

$526

BaselSeattle

BSL - SEA

BSLSEA

Basel EuroAirport Swiss

Sat 8/23

6:35 am-11:35 am

1 stop14h 00m

Seattle/Tacoma Intl

Wed 9/24

1:30 pm-10:40 pm

1 stop24h 10m

$529

BaselSeattle

BSL - SEA

BSLSEA

Basel EuroAirport Swiss

Thu 10/2

6:10 am-8:12 pm

2 stops23h 02m

Seattle/Tacoma Intl

Sat 10/18

1:35 pm-6:25 pm

1 stop19h 50m

$536

BaselSeattle

BSL - SEA

BSLSEA

Basel EuroAirport Swiss

Thu 10/2

6:15 am-4:20 pm

2 stops19h 05m

Seattle/Tacoma Intl

Sat 10/18

9:25 am-1:50 pm

2 stops19h 25m

$572

BaselSeattle

BSL - SEA

BSLSEA

Basel EuroAirport Swiss

Wed 10/8

9:45 am-4:59 pm

1 stop16h 14m

Seattle/Tacoma Intl

Sun 12/14

3:10 pm-12:25 pm

1 stop12h 15m

$670

BaselSeattle

BSL - SEA

BSLSEA

Basel EuroAirport Swiss

Fri 7/18

6:05 am-11:55 am

1 stop14h 50m

Seattle/Tacoma Intl

Wed 7/30

6:50 pm-7:35 pm

1 stop15h 45m

$680

BaselSeattle

BSL - SEA

BSLSEA

Basel EuroAirport Swiss

Sun 7/6

6:25 pm-3:50 pm

1 stop30h 25m

Seattle/Tacoma Intl

Mon 8/11

5:40 pm-9:35 am

1 stop30h 55m

$888

BaselSeattle

BSL - SEA

BSLSEA

Basel EuroAirport Swiss

Fri 9/12

6:55 pm-5:15 pm

1 stop31h 20m

Seattle/Tacoma Intl

Thu 10/2

7:10 pm-6:00 pm

1 stop37h 50m

$4,403

BaselSeattle

BSL - SEA

BSLSEA

Basel EuroAirport Swiss

Mon 7/14

7:40 pm-1:50 pm

3 stops51h 10m

$690

BaselSeattle

BSL - SEA

BSLSEA

Basel EuroAirport Swiss

Sun 8/3

7:05 am-11:30 am

1 stop13h 25m

$848

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/11

Best time to book a flight from Basel to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Basel 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 Basel EuroAirport Swiss to Seattle

Rainfall in Seattle by month

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

In terms of precipitation, rainfall in Seattle ranges from 0.7 - 6.6 inches per month. November is typically the wettest month, when rainfall can reach 6.6 in. July is typically the driest time to visit Seattle when rainfall is around 0.7 in.

Temperature in Seattle by month

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

If weather is an important factor for your trip to Seattle, 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 66.2 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 41.0 F).

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. 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 Seattle. Reviews last updated June 12, 2025.
To help decide which airline to fly from Basel to Seattle, see what other customers have to say about Delta, KLM and United Airlines. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Food

7.3

Crew

8.5

Comfort

7.9

Overall

8.0

Entertainment

7.9

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
7,950 reviews
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Food

7.3

Crew

8.5

Comfort

7.9

Overall

8.0

Entertainment

7.9

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
1,358 reviews
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Food

7.3

Crew

8.5

Comfort

7.9

Overall

8.0

Entertainment

7.9

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!
United Airlines
7.4
Good
8,790 reviews
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Food

7.3

Crew

8.5

Comfort

7.9

Overall

8.0

Entertainment

7.9

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!
Turkish Airlines
7.3
Good
3,848 reviews
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Food

7.3

Crew

8.5

Comfort

7.9

Overall

8.0

Entertainment

7.9

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!
American Airlines
7.2
Good
10,000 reviews
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Food

7.3

Crew

8.5

Comfort

7.9

Overall

8.0

Entertainment

7.9

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

Find useful and relevant information for your journey from Basel to Seattle. 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 Basel EuroAirport Swiss to Seattle round-trip?

    British Airways, at $526, was found to be the cheapest airline from Basel EuroAirport Swiss to Seattle.Alternate airlines to your destination round-trip include American Airlines and Delta. British Airways is priced at 21% lower than the current average price of a flight leaving 3 months from now.

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

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

  • How can I find direct flights from Basel to Seattle?

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

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

    Yes. Cheapflights offers flight deals from Basel to Seattle 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 Basel EuroAirport Swiss to Seattle?

    Currently, January is the cheapest month in which you can book a flight from Basel EuroAirport Swiss to Seattle (average of $238). Flying from Basel EuroAirport Swiss to Seattle in July is currently the most expensive (average of $391). 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

Traveling to a place near Basel EuroAirport Swiss?

Book flights to Basel EuroAirport Swiss if you plan to visit one of these locations
SeaTac
Tukwila
Tacoma
Lakewood
Ocean Shores
Lacey
Leavenworth
Federal Way
Lynnwood
Olympia
Shoreline
Kent
Cle Elum
Centralia
Kirkland
Aberdeen
Renton
Shelton
Silverdale
Issaquah

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