Question 1

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 2

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

Accepted Answer

Flying to Seattle from London Heathrow Airport in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $819 when looking at flights departing in the afternoon. Flights to Seattle are more costly in the evening, with an average ticket price of $859. Departure times in the evening fall within the peak daily travel times, which is why tickets can be more expensive.

Question 3

What airlines fly to Seattle?

Accepted Answer

British Airways, Delta and Virgin Atlantic are the top three most popular airlines that fly to Seattle from London Heathrow Airport according to our data. British Airways is the first choice among our users, with 43% of people opting to fly with this airline when traveling to Seattle. Keep in mind that there are 4 different airlines that fly to Seattle on a routine basis, so you have a few additional options to choose from.

Question 4

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

Accepted Answer

Lufthansa, WestJet, and Finnair are the most popular carriers operating from London Heathrow to Seattle/Tacoma Intl

Question 5

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

Accepted Answer

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

Question 6

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 7

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 8

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

Accepted Answer

On average, the least expensive day to fly to Seattle from London Heathrow Airport is on a Wednesday. momondo users have found tickets for Wednesday departures for as low as $776. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Friday is the most expensive day to depart from London Heathrow Airport because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $924.

Question 9

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

Accepted Answer

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

Question 10

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 in the early afternoon have, in the past, seen delays more frequently in comparison.

Question 11

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

Accepted Answer

As of December 2025, 15 flights take off from London Heathrow Airport and land in Seattle each day. The most common flight departure time for this route is 12:00PM, with 77% of daily flights taking off in the afternoon.

Question 12

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

Accepted Answer

You could potentially save up to 7% on your flight if you consider stops on a London Heathrow Airport to Seattle flight.

Question 13

What is the typical price of a round-trip flight between London Heathrow Airport and Seattle?

Accepted Answer

Prices are currently low for flights on this route.Typical prices usually range from $768 to $1,107.
The lowest price recently found on this route was $600.

Question 14

What is the cheapest month to fly to Seattle?

Accepted Answer

In general, February is the cheapest month to fly from London Heathrow Airport to Seattle. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $615. If you don’t want to visit Seattle in February, then you should wait until September to fly from London Heathrow Airport, when ticket prices are also cheap, with an average price of $688.

Question 15

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

Accepted Answer

111 flights are operational weekly from London Heathrow Airport to Seattle as of December 2025. The most popular departure day for this route is Tue, with 19% of flights per week taking off on this day.

Question 16

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

Accepted Answer

As of December 2025, prices for London Heathrow Airport to Seattle flights are approximately 16% more expensive when compared to flights at the same time last year.

Question 17

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 $763 when searching weeks out. 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 $699 on momondo.

Question 18

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 are updated daily.

Question 19

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

Accepted Answer

The number of operators available for flights from London Heathrow Airport to Seattle/Tacoma Intl Airport is 4 as of December 2025.

Question 20

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 21

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

Accepted Answer

The necessary travel and health documents for your Seattle/Tacoma Intl Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

Best Price Found	$662
Fastest flight time	9h 45m
Direct flights	Every day
Airports in Seattle	1 airport

Airline	Rating	Free Cancellation	Price
British Airways	PriceFrom $553	Free Cancellation	Rating 6.7 7,575 reviews	Search British Airways flights
Virgin Atlantic	PriceFrom $574	Free Cancellation	Rating 7.5 675 reviews	Search Virgin Atlantic flights
Delta	PriceFrom $575	Free Cancellation	Rating 7.9 8,008 reviews	Search Delta flights
American Airlines	PriceFrom $589	Free Cancellation	Rating 7.2 11,051 reviews	Search American Airlines flights

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

What is the typical price of a round-trip flight between London Heathrow Airport and 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 7% 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 December 2025, prices for London Heathrow Airport to Seattle flights are approximately 16% more expensive when compared to flights at the same time last year.

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

Lufthansa, WestJet, and Finnair are the most popular carriers operating from London Heathrow to Seattle/Tacoma Intl

What 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 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 which experiences the fewest number of 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 least number of delays on this route over the last 12 months; with about 6% of their flights experiencing any sort of delay.

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

As of December 2025, 15 flights take off from London Heathrow Airport and land in Seattle each day. The most common flight departure time for this route is 12:00PM, with 77% of daily flights taking off in the afternoon.

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

111 flights are operational weekly from London Heathrow Airport to Seattle as of December 2025. The most popular departure day for this route is Tue, with 19% of flights per week taking off on this day.

When to book flights from London Heathrow Airport to Seattle

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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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