Question 1

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

Accepted Answer

According to our current data, Air Canada (£470), KLM (£471), and Scandinavian Airlines (£474) offers the cheapest pricing from London Heathrow Airport to Seattle. Air Canada is priced at 17% lower than the current average price of a flight leaving 3 months from now.

Question 2

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 76 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 3

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 £622). Flying from London Heathrow Airport to Seattle in July is currently the most expensive (average of £946). 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 4

What is the cheapest day to fly from London Heathrow Airport to Seattle?

Accepted Answer

Travellers seeking maximum savings on their London Heathrow Airport to Seattle flight should consider departing on Monday evenings when fares are most often at their lowest. Sunday mornings flights should be avoided if possible as fares are typically the most expensive at this time.

Question 5

Weekly flight availability from London Heathrow Airport to Seattle

Accepted Answer

The most flights from LHR to SEA are scheduled on a Monday (22 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (11 on average).

Question 6

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 7

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 8

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

Accepted Answer

The cheapest flight price from London Heathrow Airport to Seattle is £338. On average you can expect to pay £1,992. The most popular route, (London Heathrow - Seattle/Tacoma Intl), can usually be booked for £406.

Question 9

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

Accepted Answer

Consider Aeromexico (97%), KLM (93%) or Air France (93%) when booking your flight. These represent the most reliable airlines when flying from London Heathrow Airport to Seattle.

Question 10

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 Air Canada, Air France or Finnair as they are the most popular for this route.

Question 11

What is the cheapest day to fly round-trip from London Heathrow Airport to Seattle?

Accepted Answer

Users have found that flying from London Heathrow Airport to Seattle on a Saturday typically leans towards higher prices. However, this doesn’t mean you still can’t find a deal. Flexibility with other aspects of your flight can still land a great price for your trip.

Question 12

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

Accepted Answer

Find a great deal and save up to 39% by booking at least 44 days prior to your desired departure date, rather than waiting until the week of travel. According to our data, there are a number of flights available from London Heathrow Airport to Seattle within the next two weeks, with the cheapest ticket starting at £538.

Question 13

What is the cheapest month to fly from London Heathrow Airport to Seattle?

Accepted Answer

Due to multiple factors, expect to potentially pay more when booking in August. For low rates, January can be a great choice for travel to Seattle. Flights to Seattle from London Heathrow Airport in January are about £548 on average during January, but can be found for as low as £318.

Question 14

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

Accepted Answer

It’s typically best to fly out from London Heathrow Airport to Seattle in the evening. Doing so could potentially save you 20% on the flight price compared to flying in the morning, which is usually more expensive.

Question 15

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 19 flights from London Heathrow to Seattle/Tacoma Intl per day from 13 different airlines.

Question 16

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 17

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 18

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 19

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 20

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 21

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 22

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	£468
One-way from	£389
Popular in	July
Cheapest in	February
Average price	£736
Good round-trip deal	£509 or less
Good one-way deal	£538 or less

Airline	Cheapest	Average	Flexibility	On-time
Aer Lingus	Cheapest£7	Average£648	FlexibilityNo cancel fee	On-timeN/A	Search Aer Lingus flights
Icelandair	Cheapest£347	Average£469	FlexibilityNo cancel fee	On-time76%	Search Icelandair flights
Air France	Cheapest£376	Average£551	FlexibilityNo cancel fee	On-time77%	Search Air France flights
Lufthansa	Cheapest£382	Average£477	FlexibilityNo cancel fee	On-time76%	Search Lufthansa flights
United Airlines	Cheapest£383	Average£506	FlexibilityNo cancel fee	On-time69%	Search United Airlines flights
Finnair	Cheapest£394	Average£549	FlexibilityNo cancel fee	On-time76%	Search Finnair flights
KLM	Cheapest£397	Average£560	FlexibilityNo cancel fee	On-time75%	Search KLM flights
Air Canada	Cheapest£411	Average£572	FlexibilityNo cancel fee	On-time67%	Search Air Canada flights
British Airways	Cheapest£415	Average£572	FlexibilityNo cancel fee	On-time70%	Search British Airways flights
Virgin Atlantic	Cheapest£432	Average£570	FlexibilityNo cancel fee	On-time72%	Search Virgin Atlantic flights

Cheap flights from London Heathrow Airport to Seattle from £389

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 27/8. Fares are subject to change and may not be available on all flights or dates of travel.

Cheapflights Tip: The best prices from London Heathrow to Seattle/Tacoma Intl are usually found in February or November, booked 76 days in advance, depart on a Tuesday or Wednesday and return on a Tuesday

Cheap flight deals from Heathrow to Seattle

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Find 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 2 July 2025.

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 2 July 2025.

Cheapflights Fare Finder

Use the filters below to find and compare flights from London Heathrow Airport to Seattle that are best for you.

Best time to book a flight from Heathrow to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Heathrow with our price prediction graph.

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?

Use this chart to determine the optimal time to book a return flight from Heathrow to Seattle. Price data was last updated on 27 June 2025.

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?

Find hourly flight availability from Heathrow to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 2 July 2025.

What is the cheapest day to fly from London Heathrow Airport to Seattle?

Use this chart to determine the cheapest time to fly return from Heathrow to Seattle. Price data was last updated on 29 June 2025.

Weekly flight availability from London Heathrow Airport to Seattle

Explore weekly flight availability from Heathrow to Seattle. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated 2 July 2025.

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 2 July 2025.

See what other customers who have flown with Delta, KLM, andAustrian Airlines 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?

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

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 London Heathrow Airport?

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Fly from Heathrow to Seattle on these airlines

Choose from the following airlines for your flight from Heathrow to Seattle. Flights are based on user searches made on Cheapflights and were last updated on 2 July 2025.

Top 10 airlines flying from Heathrow to Seattle

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

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

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

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

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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 2 July 2025.