Question 1

Which stopover airport offers the lowest fares from London Heathrow Airport to Seattle?

Accepted Answer

Flights via Chicago (ORD) offer the lowest average return price of £386.

Question 2

How have London Heathrow Airport to Seattle flight prices changed over time?

Accepted Answer

As of January 2026, prices for London Heathrow Airport to Seattle flights are approximately 3% cheaper when compared to flights at the same time last year.

Question 3

How many flights depart from London Heathrow Airport to Seattle on average per day?

Accepted Answer

As of January 2026, 13 flights take off from London Heathrow Airport and land in Seattle each day. The most common flight departure time for this route is 14:00, with 80% of daily flights taking off in the afternoon.

Question 4

Can stopping save me money on London Heathrow Airport to Seattle flights?

Accepted Answer

You could potentially save up to 3% on your flight if you consider stops on a London Heathrow Airport to Seattle flight.

Question 5

How often are flights from London to Seattle delayed?

Accepted Answer

Historically, on average around 13% of flights between London and Seattle have experienced a delay on any given week. The average delay length over the past 12 months has been 119 minutes.

Question 6

Which airlines fly to Seattle?

Accepted Answer

Virgin Atlantic, British Airways and KLM are the top three most popular airlines that fly to Seattle from London Heathrow Airport according to our data. Virgin Atlantic is the first choice among our users, with 52% of people opting to fly with this airline when travelling to Seattle. Keep in mind that there are 14 different airlines that fly to Seattle on a routine basis, so you have a few additional options to choose from.

Question 7

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

Accepted Answer

According to our data, Delta have had the fewest delays on this route over the last 12 months, with about 6% of their flights experiencing any sort of delay.

Question 8

What is the cheapest month to fly to Seattle?

Accepted Answer

The cheapest month to fly to Seattle from London Heathrow Airport is in February. Flight prices, which tend to average around £451, are often lower during this time because this is during the off-season. The month of September is another great option to travel to Seattle, with average flight prices from London Heathrow Airport averaging around £511.

Question 9

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

Accepted Answer

Tuesday is statistically the day of the week that experiences the fewest delays on this flight route. Wednesday has historically seen more delays on average compared to the rest of the week.

Question 10

How many flights depart from London Heathrow Airport to Seattle on average per week?

Accepted Answer

95 flights are operational weekly from London Heathrow Airport to Seattle as of January 2026. The most popular departure day for this route is Tue, with 18% of flights per week taking off on this day.

Question 11

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

Accepted Answer

Generally, flights departing in the evening tend to experience fewer delays. Flights departing in the early afternoon have, in the past, seen delays more frequently in comparison.

Question 12

What is the cheapest airline that flies from London Heathrow to Seattle/Tacoma Intl?

Accepted Answer

United Airlines and Delta are the most popular carriers operating from London Heathrow to Seattle/Tacoma Intl

Question 13

How far in advance should I book a flight to Seattle?

Accepted Answer

You are more likely to see cheaper flights to Seattle from London Heathrow Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around £565 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from London Heathrow Airport for as low as £519 on momondo.

Question 14

What is the cheapest London Heathrow to Seattle/Tacoma Intl flight route?

Accepted Answer

Fly from London Heathrow to Seattle/Tacoma Intl for the best London Heathrow - Seattle/Tacoma Intl flight prices

Question 15

Which airport is the most popular for stopovers for flights between London Heathrow Airport and Seattle?

Accepted Answer

Reykjavik (KEF) was the most common stop: 65% of momondo users choosing one-stop flights on this route connected there.

Question 16

Which stopover airport has the shortest travel time from London Heathrow Airport to Seattle?

Accepted Answer

Flights connecting via Dublin (DUB) have the shortest average one-way travel time: 13h 20m.

Question 17

What is the cheapest time of day to depart on your flight to Seattle?

Accepted Answer

According to our data, the cheapest time of day to fly to Seattle is at midday. momondo users have found flights departing from London Heathrow Airport to Seattle at midday for as low as £609. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the afternoon are often more expensive, with an average ticket price of £621.

Question 18

What is the cheapest day to depart on your flight to Seattle?

Accepted Answer

According to our data, Tuesday is the cheapest day to fly to Seattle from London Heathrow Airport. The lowest ticket price found for a Tuesday departure recently was £586. Keep in mind that prices can always vary depending on your route and whether or not you are flying domestic or international. Be sure to avoid booking your departure on a Friday as prices are generally higher than usual. According to our data, the average ticket price to Seattle on Friday is £652.

Question 19

Which stopover airport has the shortest connection time from London Heathrow Airport to Seattle?

Accepted Answer

Denver (DEN) has the shortest average stopover time for this route: 1h 31m.

Question 20

What cabin class options are available on London Heathrow to Seattle/Tacoma Intl flights?

Accepted Answer

There are 4 cabin classes available to choose from on London Heathrow to Seattle/Tacoma Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Question 21

When did momondo last update prices for flights from London Heathrow Airport to Seattle/Tacoma Intl Airport?

Accepted Answer

Prices for flights from London Heathrow Airport to Seattle/Tacoma Intl Airport were last updated today.

Question 22

How many operators does momondo search for flights from London Heathrow Airport to Seattle/Tacoma Intl Airport?

Accepted Answer

As of January 2026, there are 14 operators available to choose from for flights from London Heathrow Airport to Seattle/Tacoma Intl Airport.

Question 23

How old do you have to be to fly from London Heathrow Airport to Seattle/Tacoma Intl Airport?

Accepted Answer

The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from London Heathrow Airport to Seattle/Tacoma Intl Airport.

Question 24

What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

Accepted Answer

The travel and health documents required for your trip to Seattle/Tacoma Intl Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Seattle/Tacoma Intl Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

Best price found	£458
Fastest flight time	9h 45m
Direct flights	Every day
Airports in Seattle	1 airport

Airline	Rating	Free Cancellation	Price
Icelandair	PriceFrom £351	Free Cancellation	Rating 7.1 593 reviews	Search Icelandair flights
Air France	PriceFrom £385	Free Cancellation	Rating 7.4 1,516 reviews	Search Air France flights
KLM	PriceFrom £393	Free Cancellation	Rating 7.7 1,435 reviews	Search KLM flights
Lufthansa	PriceFrom £394	Free Cancellation	Rating 6.8 7,677 reviews	Search Lufthansa flights
United Airlines	PriceFrom £404	Free Cancellation	Rating 7.4 9,137 reviews	Search United Airlines flights
Finnair	PriceFrom £410	Free Cancellation	Rating 7.6 1,345 reviews	Search Finnair flights
Aer Lingus	PriceFrom £416	Free Cancellation	Rating 7.2 1,419 reviews	Search Aer Lingus flights
Virgin Atlantic	PriceFrom £434	Free Cancellation	Rating 7.5 678 reviews	Search Virgin Atlantic flights
British Airways	PriceFrom £437	Free Cancellation	Rating 6.7 7,641 reviews	Search British Airways flights
Delta	PriceFrom £443	Free Cancellation	Rating 7.9 8,023 reviews	Search Delta flights

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How to get the cheapest flight ticket from London Heathrow Airport to Seattle

What is the cheapest month to fly to Seattle?

What is the cheapest day to depart on your flight to Seattle?

What is the cheapest time of day to depart on your flight to Seattle?

What is the cheapest London Heathrow to Seattle/Tacoma Intl flight route?

Fly from London Heathrow to Seattle/Tacoma Intl for the best London Heathrow - Seattle/Tacoma Intl flight prices

How far in advance should I book a flight to Seattle?

What cabin class options are available on London Heathrow to Seattle/Tacoma Intl flights?

There are 4 cabin classes available to choose from on London Heathrow to Seattle/Tacoma Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on London Heathrow Airport to Seattle flights?

You could potentially save up to 3% on your flight if you consider stops on a London Heathrow Airport to Seattle flight.

How have London Heathrow Airport to Seattle flight prices changed over time?

As of January 2026, prices for London Heathrow Airport to Seattle flights are approximately 3% cheaper when compared to flights at the same time last year.

What is the cheapest airline that flies from London Heathrow to Seattle/Tacoma Intl?

United Airlines and Delta are the most popular carriers operating from London Heathrow to Seattle/Tacoma Intl

Which airlines fly to Seattle?

How often are flights from London to Seattle delayed?

Historically, on average around 13% of flights between London and Seattle have experienced a delay on any given week. The average delay length over the past 12 months has been 119 minutes.

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

Generally, flights departing in the evening tend to experience fewer delays. Flights departing in the early afternoon have, in the past, seen delays more frequently in comparison.

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

Tuesday is statistically the day of the week that experiences the fewest delays on this flight route. Wednesday has historically seen more delays on average compared to the rest of the week.

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

According to our data, Delta have had the fewest delays on this route over the last 12 months, with about 6% of their flights experiencing any sort of delay.

Which airport is the most popular for stopovers for flights between London Heathrow Airport and Seattle?

Reykjavik (KEF) was the most common stop: 65% of momondo users choosing one-stop flights on this route connected there.

Which stopover airport offers the lowest fares from London Heathrow Airport to Seattle?

Flights via Chicago (ORD) offer the lowest average return price of £386.

Which stopover airport has the shortest travel time from London Heathrow Airport to Seattle?

Flights connecting via Dublin (DUB) have the shortest average one-way travel time: 13h 20m.

Which stopover airport has the shortest connection time from London Heathrow Airport to Seattle?

Denver (DEN) has the shortest average stopover time for this route: 1h 31m.

How many flights depart from London Heathrow Airport to Seattle on average per day?

As of January 2026, 13 flights take off from London Heathrow Airport and land in Seattle each day. The most common flight departure time for this route is 14:00, with 80% of daily flights taking off in the afternoon.

How many flights depart from London Heathrow Airport to Seattle on average per week?

95 flights are operational weekly from London Heathrow Airport to Seattle as of January 2026. The most popular departure day for this route is Tue, with 18% of flights per week taking off on this day.

When to book flights from London Heathrow Airport to Seattle

Cheap London Heathrow Airport to Seattle (LHR to SEA) flight deals and tips

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When did momondo last update prices for flights from London Heathrow Airport to Seattle/Tacoma Intl Airport?

How many operators does momondo search for flights from London Heathrow Airport to Seattle/Tacoma Intl Airport?

How old do you have to be to fly from London Heathrow Airport to Seattle/Tacoma Intl Airport?

What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

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What is the most popular airline from London Heathrow Airport to Seattle?

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