Q: How much does it cost for a return flight from London Heathrow Airport to Seattle?

Airfare is below average for this route at the moment. London Heathrow Airport to Seattle flights typically cost between £715 and £557 in September. The cheapest return flight price found within the last 3 days was £518 on Delta (22 Sept-4 Mar).

Question 1

What’s the top stopover airport for flights from London Heathrow Airport to Seattle?

Accepted Answer

Reykjavik (KEF) – chosen by Cheapflights users on 64% of one-stop itineraries from London Heathrow Airport to Seattle on Cheapflights.

Question 2

How much does it cost for a return flight from London Heathrow Airport to Seattle?

Accepted Answer

Airfare is below average for this route at the moment.London Heathrow Airport to Seattle flights typically cost between £715 and £557 in September.
The cheapest return flight price found within the last 3 days was £518 on Delta (22 Sept-4 Mar).

Question 3

What is the most punctual flight time for London to Seattle flights?

Accepted Answer

Historically, flights departing in the evening are less likely to be delayed, whereas flights leaving in the early afternoon tend to experience delays more often.

Question 4

How often are flights from London to Seattle delayed?

Accepted Answer

About 10% of weekly flights between London and Seattle have experienced delays in the past year, with the average delay time being 120 minutes.

Question 5

Which airport typically offers the quickest stopover for flights from London Heathrow Airport to Seattle?

Accepted Answer

Flights via Frankfurt am Main (FRA) offer the fastest connection on this route, with an average stopover time of 1h 23m.

Question 6

What day of the week experiences the fewest flight delays on this route?

Accepted Answer

Thursday tends to have the lowest number of delays on this route, whereas Friday has historically faced a higher average of delays compared to other days of the week.

Question 7

Which airline has the best punctuality record on London to Seattle flights?

Accepted Answer

Over the past year, Delta have had the lowest number of delays on this route, with just 5% of flights being delayed.

Question 8

What’s the cheapest stopover airport for flights from London Heathrow Airport to Seattle?

Accepted Answer

Dallas (DFW) is the most affordable one-stop option, with an average return flight price of £496.

Question 9

What’s the fastest stopover option from London Heathrow Airport to Seattle?

Accepted Answer

Flights via Vancouver (YVR) have the shortest average one-way travel time for one-stop routes: 12h 36m.

Question 10

How long is the flight from London Heathrow Airport to Seattle?

Accepted Answer

Departing from London Heathrow Airport to Seattle will take you 10h 25m. The distance from London Heathrow Airport to Seattle is about 4783 mi. This flight may include one or multiple stops.

Question 11

What are the cheapest airlines flying from London Heathrow Airport to Seattle round-trip?

Accepted Answer

According to our current data, Lufthansa (£336), Icelandair (£342), and Aer Lingus (£419) offers the cheapest pricing from London Heathrow Airport to Seattle. Lufthansa is priced at 43% lower than the current average price of a flight leaving 3 months from now.

Question 12

What are the cheapest airlines to fly from London Heathrow Airport to Seattle one-way?

Accepted Answer

The cheapest airline one-way is Alaska Airlines, with whom users have recently found tickets for as low as £283. However, be on the lookout for offers from Icelandair and British Airways, as they are both options that can get you from London Heathrow Airport to Seattle for a low price.

Question 13

How far ahead should I book a flight from London Heathrow Airport to Seattle?

Accepted Answer

The best time to book flights from London Heathrow Airport to Seattle is 80 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

Question 14

What is the cheapest month to book a flight from London Heathrow Airport to Seattle?

Accepted Answer

Currently, January is the cheapest month in which you can book a flight from London Heathrow Airport to Seattle (average of £505). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of £704). 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.

Question 15

Weekly flight availability from London Heathrow Airport to Seattle

Accepted Answer

The most flights from LHR to SEA are scheduled on a Tuesday (22 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (16 on average).

Question 16

E

Accepted Answer

In terms of precipitation, rainfall in Seattle ranges from 18.0 - 168.0 inches per month. November is typically the wettest month, when rainfall can reach 168.0 mm. July is typically the driest time to visit Seattle when rainfall is around 18.0 mm.

Question 17

E

Accepted Answer

If weather is an important factor for your trip to Seattle, 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 19.0 C. Travellers hoping to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 5.0 C).

Question 18

What are the cheapest flights from London Heathrow Airport to Seattle?

Accepted Answer

The cheapest flight price from London Heathrow Airport to Seattle is £447. On average you can expect to pay £1,737. The most popular route, (London Heathrow - Seattle/Tacoma Intl), can usually be booked for £376.

Question 19

What are the most reliable airlines from London Heathrow Airport to Seattle?

Accepted Answer

Consider KLM (88%), Air France (88%) or Delta (88%) when booking your flight. These represent the most reliable airlines when flying from London Heathrow Airport to Seattle.

Question 20

What are the most popular airlines that fly from London Heathrow Airport to Seattle?

Accepted Answer

When booking a flight from London Heathrow Airport to Seattle, you may want to consider flying on Virgin Atlantic, British Airways or Icelandair as they are the most popular for this route.

Question 21

What is the cheapest time of day to fly from LHR to SEA?

Accepted Answer

When flying from London Heathrow Airport to Seattle, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

Question 22

What airport do you fly into for flights to Seattle from London Heathrow?

Accepted Answer

If you book a flight to Seattle from London Heathrow, you will be flying to Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 11.4 mi from the center of Seattle. There are 20 flights from London Heathrow to Seattle/Tacoma Intl per day from 14 different airlines.

Question 23

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

Accepted Answer

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

Question 24

How can I find direct flights from Heathrow to Seattle?

Accepted Answer

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

Question 25

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

Accepted Answer

Yes. Cheapflights offers flight deals from Heathrow to Seattle by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

Question 26

How does Cheapflights help users find flights from Heathrow to Seattle?

Accepted Answer

Deals for Heathrow to Seattle flights are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose better, like price, airport, cabin class, and plenty of other options.

Question 27

Why should you use Cheapflights to find cheap flight tickets from Heathrow to Seattle?

Accepted Answer

Cheapflights helps you find that perfect flight to Seattle from Heathrow by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Question 28

Can Cheapflights find flights from Heathrow to Seattle with no change fees?

Accepted Answer

Need flexible booking options for your flight to Seattle from Heathrow? Don’t worry, Cheapflights have you covered. Use our search filter to only show flights with no change fees.

Question 29

Can Cheapflights notify me if prices for flights from Heathrow to Seattle become cheaper?

Accepted Answer

Yes! Start tracking prices for Heathrow to Seattle flights today and get alerted whenever prices for these flights change. To access this feature, click the bell icon next to the flight deals above, which will prompt you for a valid email address to receive your alerts.

Round-trip from	£518
One-way from	£422
Popular in	July
Cheapest in	January
Average price	£648
Good round-trip deal	£598 or less
Good one-way deal	£604 or less

Airline	Cheapest	Average	Flexibility	On-time
Lufthansa	Cheapest£336	Average£504	FlexibilityNo cancel fee	On-time76%	Search Lufthansa flights
Icelandair	Cheapest£342	Average£473	FlexibilityNo cancel fee	On-time76%	Search Icelandair flights
Aer Lingus	Cheapest£419	Average£699	FlexibilityNo cancel fee	On-timeN/A	Search Aer Lingus flights
Virgin Atlantic	Cheapest£428	Average£592	FlexibilityNo cancel fee	On-time72%	Search Virgin Atlantic flights
KLM	Cheapest£438	Average£635	FlexibilityNo cancel fee	On-time75%	Search KLM flights
Air France	Cheapest£452	Average£651	FlexibilityNo cancel fee	On-time77%	Search Air France flights
Delta	Cheapest£465	Average£616	FlexibilityNo cancel fee	On-timeN/A	Search Delta flights
British Airways	Cheapest£465	Average£640	FlexibilityNo cancel fee	On-time70%	Search British Airways flights
Air Canada	Cheapest£465	Average£500	FlexibilityNo cancel fee	On-time67%	Search Air Canada flights
United Airlines	Cheapest£468	Average£685	FlexibilityNo cancel fee	On-time69%	Search United Airlines flights

Cheap flights from London Heathrow Airport to Seattle from £422

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 21/6. Fares are subject to change and may not be available on all flights or dates of travel.

Cheap flight deals from Heathrow to Seattle

Cheapest flights from Heathrow to SeattleExplore the most affordable flight options available from Heathrow to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 9 June 2026.

Explore the most affordable flight options available from Heathrow to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 9 June 2026.

Best flights from Heathrow to SeattleDiscover carefully curated flight deals from Heathrow to Seattle that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 9 June 2026.

Discover carefully curated flight deals from Heathrow to Seattle that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 9 June 2026.

Direct flights from Heathrow to SeattleExplore direct flight options from Heathrow to Seattle based on user searches, and compare prices and availability for your desired travel dates. Data last updated 9 June 2026.

Explore direct flight options from Heathrow to Seattle based on user searches, and compare prices and availability for your desired travel dates. Data last updated 9 June 2026.

Last-minute flights from Heathrow to SeattleDiscover last-minute flight deals from Heathrow to Seattle. Data last updated 9 June 2026 and is based on user searches.

Discover last-minute flight deals from Heathrow to Seattle. Data last updated 9 June 2026 and is based on user searches.

One-way flights from Heathrow to SeattleSearch for one-way flight options from Heathrow to Seattle. Find affordable one-way fares based on user searches. Data last updated 9 June 2026.

Search for one-way flight options from Heathrow to Seattle. Find affordable one-way fares based on user searches. Data last updated 9 June 2026.

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Best time to book a flight from Heathrow to Seattle

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Cheapflights Insights

Everything you need to know about your flight from London Heathrow Airport to Seattle

How far ahead should I book a flight from London Heathrow Airport to Seattle?

What is the cheapest month to book a flight from London Heathrow Airport to Seattle?

What is the cheapest time of day to fly from LHR to SEA?

How much does it cost for a return flight from London Heathrow Airport to Seattle?

Weekly flight availability from London Heathrow Airport to Seattle

How often are flights from London to Seattle delayed?

What is the most punctual flight time for London to Seattle flights?

What day of the week experiences the fewest flight delays on this route?

Which airline has the best punctuality record on London to Seattle flights?

What’s the top stopover airport for flights from London Heathrow Airport to Seattle?

What’s the cheapest stopover airport for flights from London Heathrow Airport to Seattle?

What’s the fastest stopover option from London Heathrow Airport to Seattle?

Which airport typically offers the quickest stopover for flights from London Heathrow Airport to Seattle?

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. 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 Seattle. Reviews last updated 9 June 2026.

See what other customers who have flown with KLM,Virgin Atlantic, andAir France from London Heathrow Airport to Seattle have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

Find useful and relevant information for your journey from Heathrow to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

What airport do you fly into for flights to Seattle from London Heathrow?

How long is the flight from London Heathrow Airport to Seattle?

What are the cheapest airlines flying from London Heathrow Airport to Seattle round-trip?

What are the cheapest airlines to fly from London Heathrow Airport to Seattle one-way?

What are the most reliable airlines from London Heathrow Airport to Seattle?

What are the cheapest flights from London Heathrow Airport to Seattle?

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

How can I find direct flights from Heathrow to Seattle?

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

What is the cheapest month to book a flight from London Heathrow Airport to Seattle?

Travelling to a place near Seattle?

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Fly from Heathrow to Seattle on these airlines

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Alternative routes for Heathrow to Seattle

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Complete your trip

Complete your trip to Seattle by adding a car hire and/or hotel booking to your travel itinerary.

Direct flights to Washington

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Search flights from Heathrow to Seattle by cabin class

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Heathrow and Seattle flights

Browse other Heathrow and Seattle flight options. Last updated on 9 June 2026.

Other flights from Heathrow

Browse through other flights departing from Heathrow. Flights are based on user searches made on Cheapflights and were last updated on 9 June 2026.

Popular flight searches

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Other flights to Seattle

Explore flights to Seattle departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on 9 June 2026.

Top 10 airlines flying from Heathrow to Seattle

Fly with Cheapflights

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How does Cheapflights help users find flights from Heathrow to Seattle?

Cheapest flights from Heathrow to Seattle
Explore the most affordable flight options available from Heathrow to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 9 June 2026.

Best flights from Heathrow to Seattle
Discover carefully curated flight deals from Heathrow to Seattle that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 9 June 2026.

Direct flights from Heathrow to Seattle
Explore direct flight options from Heathrow to Seattle based on user searches, and compare prices and availability for your desired travel dates. Data last updated 9 June 2026.

Last-minute flights from Heathrow to Seattle
Discover last-minute flight deals from Heathrow to Seattle. Data last updated 9 June 2026 and is based on user searches.

One-way flights from Heathrow to Seattle
Search for one-way flight options from Heathrow to Seattle. Find affordable one-way fares based on user searches. Data last updated 9 June 2026.