The cheapest times to fly from SEA to BSL are

  • January 1st to April 1st
  • April 16th to May 13th
  • October 8th to December 9th

based on data collected exclusively by Champion Traveler across tens of millions of flights. Among all the dates above, the very cheapest time to fly from SEA to BSL is early to mid May. Prices can be as high as $1708 for Saturday flights during late May, or as low as $475 for Tuesday flights around early to mid May.


When to Fly to Basel

Flying from Seattle, WA (SEA) to Mulhouse (BSL) will usually cost between $729 to $1379 per person if booking more than four weeks in advance. On average the very cheapest time to fly is early to mid May with an average ticket price of $668. Due to high demand the most expensive time to fly is late May, with an average price of $1469. Planning your trip to low-cost times can easily save you $801 on economy flights and even more on first-class flights. Generally, any price below $858 can be considered a good price for a round-trip SEA to BSL flight.

See below for a graph of average weekly prices for the SEA to BSL route. All prices are for round-trip tickets in USD.

SEA to BSL Flight Prices

Compared to other flights, the SEA to BSL flight is cheaper than the average and costs less than the average flight leaving from Seattle. The average price per mile (for a direct flight) is $0.1, which is far below average.


Flight Prices by Day of the Week

Tuesday is usually the cheapest day to depart and return on this flight. Saturdays are the most expensive days to fly to Basel, and Fridays are the most expensive days to return to Seattle. Selecting flights on the least expensive days could save you up to $102 (10%) on this flight.

Departing prices are for round-trip flights returning on the day of departure. For example, a flight departing on Tuesday and returning a week later will cost an average of $909. Return trip prices are from the BSL to SEA flight, and often highlight the quality of our data in showing the same trend.

Departing Prices by Day

Departure Day Prices

Return Trip Prices by Day

Return Day Prices


Nonstop Flights and Layovers

Travelers looking to fly from SEA to BSL can generally find a 1-layover flight. Because there is not usually a direct flight option the real-world direct flight time of 10 hour 22 minutes may not be realistic.


Alternative Nearby Airports

Champion Traveler tells you which airports are nearby and whether tickets might be cheaper alternative airports nearby. Sometimes it’s worth it to fly into a closer airport and then commute to your destination. Remember that there is not usually a nonstop flight from SEA to BSL while comparing.

Destination alternative #1: Zurich Airport (ZRH) in Zurich

  • 48 miles (77 km) away from BSL
  • Usually 11.84% less expensive than BSL
  • 1-layover flights available

See SEA to ZRH flights

Destination alternative #2: Malpensa Airport (MXP) in Milan

  • 147 miles (237 km) away from BSL
  • Usually 0.64% less expensive than BSL
  • 1-layover flights available

See SEA to MXP flights


Flight Hacking SEA to BSL

Flight hacking is when you book two tickets instead of a layover, sometimes with different airlines. You will need to either bring only a carry-on bag (highly recommended) or leave yourself plenty of time to go through security again. Flight hacking is completely allowed, but airlines don’t always tell you the cheapest way to get from SEA to BSL — but Champion Traveler does!

Hack #1: London (SEA > LHR > BSL)

  • Price for both tickets: $604
  • Average savings: $254 (29.56%)

See SEA to LHR flights

Hack #2: London (SEA > LGW > BSL)

  • Price for both tickets: $616
  • Average savings: $242 (28.22%)

See SEA to LGW flights

Hack #3: Manchester (SEA > MAN > BSL)

  • Price for both tickets: $727
  • Average savings: $131 (15.22%)

See SEA to MAN flights


Flight Questions Answered

Still have questions about flying from SEA to BSL? We’ve got answers.

Which airlines fly this route?

You can find 17 major airlines flying this route most often: Air Canada, Air France, Alaska, American, Austrian, British Airways, Brussels Airlines, Condor, Delta, Finnair, Iberia, KLM, Lufthansa, SWISS, Tap Air Portugal, Turkish Airlines, United, and potentially more during busy seasons.

How far away is it from Euro Airport to Seattle/Tacoma International Airport?

The distance between the two airports is roughly 5210 miles or 8385 kilometers.

How long does it take to fly from SEA to BSL?

The real-world flight time for a nonstop SEA to BSL flight is about 10 hour 22 minutes.

How many flights go between Seattle, WA and Mulhouse?

It depends on the day of the week and the date, but a typical day might have around 18 available flights from SEA to BSL.


Airport Location Info


Departing Airport

Origination codeSEA
Origination airport nameSeattle/Tacoma International Airport
CitySeattle, WA
Countrythe United States

Return Airport

Destination codeBSL
Destination airport nameEuro Airport


Other Resources

Please note that while we’ve worked hard to analyzed tens of millions of flights to get you this data, we do not calculate current live prices or guarantee pricing. Please see our partners using the links above for current offers.