The cheapest times to fly from SEA to KEF are

  • January 1st to February 11th (except the week of January 8th)
  • March 26th to June 10th (except the weeks of April 2nd, May 7th, and May 14th)
  • July 2nd to July 22nd
  • August 13th to October 7th

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 KEF is early to mid September. Prices can be as high as $4437 for Wednesday flights during mid December, or as low as $500 for Tuesday flights around early to mid September.


When to Fly to Reykjavík

Flying from Seattle, WA (SEA) to Keflavik/Reykjavik (KEF) will usually cost between $512 to $711 per person if booking more than four weeks in advance. On average the very cheapest time to fly is early to mid September with an average ticket price of $513. Due to high demand the most expensive time to fly is mid December, with an average price of $1306. Planning your trip to low-cost times can easily save you $793 on economy flights and even more on first-class flights. Generally, any price below $603 can be considered a good price for a round-trip SEA to KEF flight.

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

SEA to KEF Flight Prices

Compared to other flights, the SEA to KEF 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 fly to KEF, and Monday the cheapest day to fly back into SEA. Wednesdays are the most expensive days to fly to Reykjavík, and Saturdays are the most expensive days to return to Seattle. Selecting flights on the least expensive days could save you up to $62 (9%) 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 $580. Return trip prices are from the KEF 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 KEF can generally find a 0-layover flight. Because there is a direct flight option the real-world direct flight time of 7 hour 29 minutes may be realistic.


Flight Questions Answered

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

Which airlines fly this route?

You can find 13 major airlines flying this route most often: Air Canada, Air France, Alaska, American, British Airways, Delta, Icelandair, JetBlue, KLM, Lufthansa, Singapore Airlines, United, Virgin Atlantic, and potentially more during busy seasons.

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

The distance between the two airports is roughly 3610 miles or 5810 kilometers.

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

The real-world flight time for a nonstop SEA to KEF flight is about 7 hour 29 minutes.

How many flights go between Seattle, WA and Keflavik/Reykjavik?

It depends on the day of the week and the date, but a typical day might have around 69 available flights from SEA to KEF.


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 KEF
Destination airport name Keflavik International Airport
City Keflavik/Reykjavik
Country Iceland
Latitude 64
Longitude -22.6


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.