The cheapest times to fly from SEA to KMJ are

  • January 8th to May 6th (except the week of April 16th)
  • September 10th to October 7th
  • October 29th 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 KMJ is mid March. Prices can be as high as $2092 for Saturday flights during early August, or as low as $1119 for Monday flights around mid March.


When to Fly to Kumamoto

Flying from Seattle, WA (SEA) to Kumamoto (KMJ) will usually cost between $1119 to $1625 per person if booking more than four weeks in advance. On average the very cheapest time to fly is mid March with an average ticket price of $1204. Due to high demand the most expensive time to fly is early August, with an average price of $1725. Planning your trip to low-cost times can easily save you $521 on economy flights and even more on first-class flights. Generally, any price below $1319 can be considered a good price for a round-trip SEA to KMJ flight.

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

SEA to KMJ Flight Prices

Compared to other flights, the SEA to KMJ flight is slightly more expensive than the average and costs slightly more than the average flight leaving from Seattle. The average price per mile (for a direct flight) is $0.16, which is far below average.


Flight Prices by Day of the Week

Monday is usually the cheapest day to fly to KMJ, and Tuesday the cheapest day to fly back into SEA. Saturdays are the most expensive days to fly out or take a return trip. Selecting flights on the least expensive days could save you up to $211 (14%) on this flight.

Departing prices are for round-trip flights returning on the day of departure. For example, a flight departing on Monday and returning a week later will cost an average of $1214. Return trip prices are from the KMJ 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 KMJ 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 29 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 KMJ while comparing.

Destination alternative #1: Fukuoka Airport (FUK) in Fukuoka

  • 57 miles (92 km) away from KMJ
  • Usually 18.58% less expensive than KMJ
  • 1-layover flights available

See SEA to FUK flights

Destination alternative #2: Matsuyama Airport (MYJ) in Matsuyama

  • 127 miles (204 km) away from KMJ
  • Usually 0.42% less expensive than KMJ
  • 1-layover flights available

See SEA to MYJ flights


Flight Hacking SEA to KMJ

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 KMJ — but Champion Traveler does!

Hack #1: Osaka (SEA > KIX > KMJ)

  • Price for both tickets: $971
  • Average savings: $348 (26.36%)

See SEA to KIX flights

Hack #2: Tokyo (SEA > NRT > KMJ)

  • Price for both tickets: $1019
  • Average savings: $300 (22.72%)

See SEA to NRT flights

Hack #3: Nagoya (SEA > NGO > KMJ)

  • Price for both tickets: $1150
  • Average savings: $169 (12.78%)

See SEA to NGO flights


Flight Questions Answered

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

Which airlines fly this route?

You can find 8 major airlines flying this route most often: American, ANA, Asiana, Delta, Garuda Indonesia, Hawaiian, JAL, United, and potentially more during busy seasons.

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

The distance between the two airports is roughly 5279 miles or 8496 kilometers.

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

The real-world flight time for a nonstop SEA to KMJ flight is about 10 hour 29 minutes.

How many flights go between Seattle, WA and Kumamoto?

It depends on the day of the week and the date, but a typical day might have around 16 available flights from SEA to KMJ.


Airport Location Info


Departing Airport

Origination code SEA
Origination airport name Seattle/Tacoma International Airport
City Seattle, WA
Country the United States
Latitude 47.5
Longitude -122.3

Return Airport

Destination code KMJ
Destination airport name Kumamoto Airport
City Kumamoto
Country Japan
Latitude 32.8
Longitude 130.9


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.