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$402+ 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 7/22. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BSL
jun. 17 — jun. 241
mar. 6/17
mar. 6/24
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 junio 12, 2025.

Round-trip from

$513
(Lufthansa)

One-way from

$402
(Delta)

Popular in

June

Cheapest in

November

Average price

$966
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. 12% potential increase in price ($99 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 June 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 junio 12, 2025.

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.
lun. 8/182:20 pmSEA - BSL
1 stop14h 20mLufthansa
mar. 8/268:30 amBSL - SEA
2 stops21h 12mLufthansa
Deal found 6/10$513
This Delta 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 8/186:40 pmSEA - BSL
1 stop33h 30mDelta
mar. 8/2610:10 amBSL - SEA
1 stop16h 25mDelta
Deal found 6/10$518
This British Airways 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 British Airways is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 8/191:30 pmSEA - BSL
1 stop12h 25mBritish Airways
mar. 8/266:45 amBSL - SEA
1 stop13h 25mBritish Airways
Deal found 6/10$533
This Booking.com 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 9/110:00 amSEA - BSL
2 stops22h 50mMultiple Airlines
lun. 9/156:30 pmBSL - SEA
1 stop26h 25mMultiple Airlines
Deal found 6/11$555
This United 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 9/15:07 amSEA - BSL
2 stops29h 28mUnited Airlines
lun. 9/1511:30 amBSL - SEA
2 stops35h 46mUnited Airlines
Deal found 6/10$556
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.
lun. 12/86:50 pmSEA - BSL
1 stop14h 20mAmerican Airlines
vie. 12/264:00 pmBSL - SEA
1 stop28h 20mAmerican Airlines
Deal found 6/11$591
This Expedia 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 8/215:40 pmSEA - BSL
1 stop15h 10mAir France
mar. 8/2610:10 amBSL - SEA
1 stop16h 25mAir France
Deal found 6/10$619
This Gurufare 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 Gurufare is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 9/14:25 pmSEA - BSL
2 stops30h 25mSWISS
lun. 9/158:25 amBSL - SEA
2 stops19h 11mSWISS
Deal found 6/11$652
This KLM 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 7/311:30 pmSEA - BSL
1 stop14h 40mKLM
lun. 8/116:25 pmBSL - SEA
1 stop30h 30mKLM
Deal found 6/10$734
This FlightHub 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 7/512:30 pmSEA - BSL
1 stop36h 10mTurkish Airlines
vie. 7/116:55 pmBSL - SEA
1 stop24h 40mTurkish Airlines
Deal found 6/11$905
This Air Canada 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 7/31:45 pmSEA - BSL
2 stops36h 10mAir Canada
mié. 7/911:25 amBSL - SEA
2 stops18h 16mAir Canada
Deal found 6/11$941

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 junio 12, 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

lun. 8/18

2:20 pm-1:40 pm

1 stop14h 20m

Basel EuroAirport Swiss

mar. 8/26

8:30 am-8:42 pm

2 stops21h 12m

$513

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

lun. 8/18

6:40 pm-1:10 pm

1 stop33h 30m

Basel EuroAirport Swiss

mar. 8/26

10:10 am-5:35 pm

1 stop16h 25m

$518

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

mar. 8/19

1:30 pm-10:55 am

1 stop12h 25m

Basel EuroAirport Swiss

mar. 8/26

6:45 am-11:10 am

1 stop13h 25m

$533

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

lun. 8/18

7:00 am-12:25 pm

2 stops20h 25m

Basel EuroAirport Swiss

lun. 8/25

11:30 am-5:58 pm

2 stops39h 28m

$536

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

lun. 9/1

10:00 am-5:50 pm

2 stops22h 50m

Basel EuroAirport Swiss

lun. 9/15

6:30 pm-11:55 am

1 stop26h 25m

$555

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

lun. 12/8

6:50 pm-6:10 pm

1 stop14h 20m

Basel EuroAirport Swiss

vie. 12/26

4:00 pm-11:20 am

1 stop28h 20m

$591

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

jue. 8/21

5:40 pm-5:50 pm

1 stop15h 10m

Basel EuroAirport Swiss

mar. 8/26

10:10 am-5:35 pm

1 stop16h 25m

$619

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

lun. 9/1

4:25 pm-7:50 am

2 stops30h 25m

Basel EuroAirport Swiss

lun. 9/15

8:25 am-6:36 pm

2 stops19h 11m

$652

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

jue. 7/31

1:30 pm-1:10 pm

1 stop14h 40m

Basel EuroAirport Swiss

lun. 8/11

6:25 pm-3:55 pm

1 stop30h 30m

$734

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

sáb. 7/5

12:30 pm-9:40 am

1 stop36h 10m

Basel EuroAirport Swiss

vie. 7/11

6:55 pm-10:35 am

1 stop24h 40m

$905

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/10

Showing 1-10 of 18 results
1
2

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 junio 12, 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 junio 12, 2025.
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!
Air France
7.5
Good
1,463 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!
SWISS
7.5
Good
1,623 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!

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?

    Lufthansa, at $513, was found to be the cheapest airline from Seattle to Basel EuroAirport Swiss.Alternate airlines to your destination round-trip include Delta and British Airways. You may be able to fly from Seattle to Basel EuroAirport Swiss for 27% 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 $402 on Delta. Other airlines that offer cheap prices include United Airlines from $409 and Lufthansa from $460 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

Browse thousands of different options on Cheapflights for your next trip

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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 junio 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest$443Average$694FlexibilityNo cancel feeOn-time70%
DeltaCheapest$513Average$741FlexibilityNo cancel feeOn-timeN/A
LufthansaCheapest$571Average$649FlexibilityNo cancel feeOn-time76%

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