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$347+ Cheap flights from Seattle (SEA) to Basel EuroAirport Swiss (BSL)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 9/15. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BSL
May 4 — May 111
Sun 5/4
Sun 5/11
1 adult, Economy
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Cheap flight deals from Seattle to Basel

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Basel (BSL). 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 April 29, 2025.

Most accurate provider

AranGrant
3 stars

Most trusted provider

AranGrant
3 stars

Round-trip from

$637
(Vakatrip)

One-way from

$422
(Air France)

Popular in

June

Cheapest in

November

Average price

$836
Provider with most accurate pricing for Seattle/Tacoma Intl-Basel EuroAirport Swiss flight deals.
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Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Basel EuroAirport Swiss flights.
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From Seattle/Tacoma Intl to Basel EuroAirport Swiss
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One-way flight from Seattle/Tacoma Intl to Basel EuroAirport Swiss
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Highest demand for flights based on searches. 13% potential increase in price ($107 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($24 potential savings vs. average RT price).
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Average for round-trip flights in April 2025
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Find flight deals from Seattle to Basel

Cheapest flights from Seattle to Basel
Explore the most affordable flight options available from Seattle to Basel. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 29, 2025.

This Gotogate deal was found by Cheapflights users on 4/27. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/42:55 pmSEA - BSL
2 stops19h 40mMultiple Airlines
Wed 6/118:25 amBSL - SEA
2 stops19h 08mMultiple Airlines
Deal found 4/27$735
This Kiwi.com deal was found by Cheapflights users on 4/27. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/272:15 pmSEA - BSL
1 stop18h 35mLufthansa
Tue 6/36:05 amBSL - SEA
2 stops17h 08mLufthansa
Deal found 4/27$759
This American Airlines deal was found by Cheapflights users on 4/27. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/278:20 pmSEA - BSL
1 stop17h 30mAmerican Airlines
Tue 6/36:45 amBSL - SEA
1 stop13h 25mAmerican Airlines
Deal found 4/27$760
This British Airways deal was found by Cheapflights users on 4/27. 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 British Airways is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/41:30 pmSEA - BSL
1 stop24h 10mBritish Airways
Tue 6/107:10 pmBSL - SEA
1 stop25h 25mBritish Airways
Deal found 4/27$762
This Delta deal was found by Cheapflights users on 4/27. 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 7/136:30 pmSEA - BSL
1 stop30h 00mDelta
Tue 8/52:25 pmBSL - SEA
1 stop30h 10mDelta
Deal found 4/27$772
This United Airlines deal was found by Cheapflights users on 4/27. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/46:25 amSEA - BSL
3 stops21h 00mUnited Airlines
Wed 6/111:00 pmBSL - SEA
2 stops18h 42mUnited Airlines
Deal found 4/27$788
This KLM deal was found by Cheapflights users on 4/27. 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 7/131:50 pmSEA - BSL
1 stop19h 00mKLM
Mon 8/42:25 pmBSL - SEA
1 stop30h 10mKLM
Deal found 4/27$852
This Austrian Airlines deal was found by Cheapflights users on 4/27. 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 Austrian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/118:00 amSEA - BSL
2 stops26h 45mAustrian Airlines
Wed 6/188:25 pmBSL - SEA
2 stops31h 28mAustrian Airlines
Deal found 4/27$1,417
This SWISS deal was found by Cheapflights users on 4/28. 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 SWISS is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/121:45 pmSEA - BSL
2 stops33h 05mSWISS
Thu 6/198:25 amBSL - SEA
2 stops19h 11mSWISS
Deal found 4/28$6,032

Cheapflights Fare Finder

Customize your flight search to find flights from Seattle to Basel 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 April 29, 2025.
Use the filters below to find and compare flights from Seattle to Basel EuroAirport Swiss that are best for you.

Fly from

Seattle

Fly to

Basel

Route

Depart

Return

Price

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Wed 6/4

2:55 pm-7:35 pm

2 stops19h 40m

Basel EuroAirport Swiss

Wed 6/11

8:25 am-6:33 pm

2 stops19h 08m

$735

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Tue 5/27

2:15 pm-5:50 pm

1 stop18h 35m

Basel EuroAirport Swiss

Tue 6/3

6:05 am-2:13 pm

2 stops17h 08m

$759

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Tue 5/27

8:20 pm-10:50 pm

1 stop17h 30m

Basel EuroAirport Swiss

Tue 6/3

6:45 am-11:10 am

1 stop13h 25m

$760

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Wed 6/4

1:30 pm-10:40 pm

1 stop24h 10m

Basel EuroAirport Swiss

Tue 6/10

7:10 pm-11:35 am

1 stop25h 25m

$762

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Sun 7/13

6:30 pm-9:30 am

1 stop30h 00m

Basel EuroAirport Swiss

Tue 8/5

2:25 pm-11:35 am

1 stop30h 10m

$772

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Wed 6/4

6:25 am-12:25 pm

3 stops21h 00m

Basel EuroAirport Swiss

Wed 6/11

1:00 pm-10:42 pm

2 stops18h 42m

$788

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Sun 7/13

1:50 pm-5:50 pm

1 stop19h 00m

Basel EuroAirport Swiss

Mon 8/4

2:25 pm-11:35 am

1 stop30h 10m

$852

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Wed 6/11

8:00 am-7:45 pm

2 stops26h 45m

Basel EuroAirport Swiss

Wed 6/18

8:25 pm-6:53 pm

2 stops31h 28m

$1,417

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Thu 6/12

1:45 pm-7:50 am

2 stops33h 05m

Basel EuroAirport Swiss

Thu 6/19

8:25 am-6:36 pm

2 stops19h 11m

$6,032

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Mon 9/15

7:00 pm-10:35 pm

3 stops42h 35m

$347

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/28

Showing 1-10 of 16 results
1
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Compare providers for flights from Seattle to Basel

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 Basel in April.
ProviderPrice AccuracyTrust Score*
AranGrantPrice Accuracy3 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*2 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-Basel EuroAirport Swiss flights, users find the pricing of AranGrant to be most consistent on Cheapflights vs. AranGrant Users can find the same prices on Seattle-Basel EuroAirport Swiss flight deals on Cheapflights vs. AranGrant >95% of the time. Price accuracy is based on data collected from Seattle-Basel EuroAirport Swiss flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-Basel EuroAirport Swiss flights, Cheapflights users trust AranGrant the most. AranGrant 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-Basel EuroAirport Swiss 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 Basel

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

What is the cheapest month to book a flight from Seattle to Basel EuroAirport Swiss?

Currently, January is the cheapest month in which you can book a flight from Seattle to Basel EuroAirport Swiss (average of $545). Flying from Seattle to Basel EuroAirport Swiss in June is currently the most expensive (average of $1,132). 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 time of day to fly from SEA to BSL?

Find hourly flight availability from Seattle to Basel. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated April 29, 2025.

A simple way to save on the total cost of your ticket is to fly from Seattle to Basel EuroAirport Swiss in the evening. If you’re flexible enough to do this you can expect to save up to 24% on your trip compared to booking a flight in the afternoon.

Rainfall in Basel by month

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

In terms of precipitation, rainfall in Basel EuroAirport Swiss ranges from 1.9 - 3.4 inches per month. June is typically the wettest month, when rainfall can reach 3.4 in. February is typically the driest time to visit Basel EuroAirport Swiss when rainfall is around 1.9 in.

Temperature in Basel by month

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

If weather is an important factor for your trip to Basel EuroAirport Swiss, 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 January, when temperatures are typically at their lowest (around 33.8 F).

Reviews of airlines servicing Basel

Get insights into the airlines that provide service to Basel. 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 Basel. Reviews last updated April 29, 2025.
Delta
8.0
Very good
7,929 reviews

Comfort

7.9

Food

7.3

Boarding

8.2

Entertainment

7.9

Overall

8.0

Crew

8.5

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
7,929 reviews
Delta
8.0
Very good
7,929 reviews

Comfort

7.9

Food

7.3

Boarding

8.2

Entertainment

7.9

Overall

8.0

Crew

8.5

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
1,333 reviews
Delta
8.0
Very good
7,929 reviews

Comfort

7.9

Food

7.3

Boarding

8.2

Entertainment

7.9

Overall

8.0

Crew

8.5

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.
SWISS
7.5
Good
1,587 reviews
Delta
8.0
Very good
7,929 reviews

Comfort

7.9

Food

7.3

Boarding

8.2

Entertainment

7.9

Overall

8.0

Crew

8.5

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.
Air France
7.4
Good
1,444 reviews
Delta
8.0
Very good
7,929 reviews

Comfort

7.9

Food

7.3

Boarding

8.2

Entertainment

7.9

Overall

8.0

Crew

8.5

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.
United Airlines
7.4
Good
8,696 reviews
Delta
8.0
Very good
7,929 reviews

Comfort

7.9

Food

7.3

Boarding

8.2

Entertainment

7.9

Overall

8.0

Crew

8.5

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 Basel. 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 Basel EuroAirport Swiss round-trip?

    Turkish Airlines, at $637, was found to be the cheapest airline from Seattle to Basel EuroAirport Swiss.Alternate airlines to your destination round-trip include Lufthansa and American Airlines. You may be able to fly from Seattle to Basel EuroAirport Swiss for 9% less than the average price by searching for these airlines.

  • What are the cheapest airlines to fly from Seattle to Basel EuroAirport Swiss one-way?

    One-way options have recently been found by users for as low as $422 on Air France. Other airlines that offer cheap prices include Delta from $426 and Lufthansa from $456 one-way.

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

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

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

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

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

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

    Currently, January is the cheapest month in which you can book a flight from Seattle to Basel EuroAirport Swiss (average of $545). Flying from Seattle to Basel EuroAirport Swiss in June is currently the most expensive (average of $1,132). 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 Basel

See prices for flight routes from nearby airports that may be better suited for you.
Portland to Basel flights

Top 3 airlines flying from Seattle to Basel

Discover the top 3 airlines that operate flights from Seattle to Basel. 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 April 29, 2025.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest$443Average$694FlexibilityNo cancel feeOn-time70%
Air FranceCheapest$502Average$769FlexibilityNo cancel feeOn-time77%
DeltaCheapest$513Average$741FlexibilityNo cancel feeOn-timeN/A

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