Question 1

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

Accepted Answer

Cheapflights users have booked flights from Seattle to London round-trip from £435. Other airlines that can offer you cheap pricing are Delta, from £435, and Icelandair, from £436. Virgin Atlantic is currently priced 23% below the average price you’ll pay for this route.

Question 2

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

Accepted Answer

The cheapest airline one-way is Icelandair, with whom users have recently found tickets for as low as £182. However, be on the lookout for offers from WestJet and SWISS, as they are both options that can get you from Seattle to London for a low price.

Question 3

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

Accepted Answer

The price you pay for your flight from Seattle to London may vary depending on when you book. For the best chance of a lower fare, look to book 81 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

Question 4

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

Accepted Answer

Currently, January is the cheapest month in which you can book a flight from Seattle to London (average of £112). Flying from Seattle to London in August is currently the most expensive (average of £164). 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 5

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

Accepted Answer

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

Question 6

Weekly flight availability from Seattle to London

Accepted Answer

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

Question 7

E

Accepted Answer

In terms of precipitation, rainfall in London ranges from 40.0 - 70.0 inches per month. January is typically the wettest month, when rainfall can reach 70.0 mm. July is typically the driest time to visit London when rainfall is around 40.0 mm.

Question 8

E

Accepted Answer

If weather is an important factor for your trip to London, 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 17.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 4.0 C).

Question 9

What are the most popular routes from Seattle to London?

Accepted Answer

The most popular route from Seattle to London is Seattle/Tacoma Intl - London Heathrow. You may also consider Seattle/Tacoma Intl - London Gatwick or Seattle/Tacoma Intl - London City.

Question 10

What are the cheapest flights from Seattle to London?

Accepted Answer

The cheapest flight price from Seattle to London is £307. On average you can expect to pay £1,204. The most popular route, (Seattle/Tacoma Intl - London Heathrow), can usually be booked for £348.

Question 11

What are the most reliable airlines from Seattle to London?

Accepted Answer

No one likes to see their flight delayed. When booking a flight from Seattle to London consider choosing Aeromexico (92%), KLM (88%) or Air France (88%) as they are the most reliable in getting you off to your destination on time.

Question 12

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

Accepted Answer

The most popular airlines flying from Seattle to London are British Airways, Icelandair and Virgin Atlantic. Something to consider prior to booking your flight.

Question 13

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

Accepted Answer

Flying to your destination on a Thursday can be more expensive, but this shouldn’t discourage you from finding affordable options to get to London. Check prices with Cheapflights to find a great deal for your trip.

Question 14

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

Accepted Answer

Travelers have found it’s best to book a flight 51 days in advance to save up to 38% compared to booking the same week of travel. As your travel date approaches, the cost of this flight route may potentially increase. While opting to book 51 days out may not be an option for all, there are still additional ways to secure a deal in the near future. You might find a flight from Seattle to London 1-2 weeks in advance for as low as £621, or £721 for flights within the next 24 hours.

Question 15

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

Accepted Answer

The best pricing can be found in the month of October. Prices to London from Seattle average £569. You can even find prices in October for less than £569, as users have found deals to London from as low as £394. The month of June appears to be one of the more expensive times to travel to London from Seattle. Flying in the targeted month can save you up to 32%.

Question 16

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

Accepted Answer

One of the essential ways to save on airfare from Seattle to London is to remain as flexible as possible. Flights that are in the morning tend to be the most expensive. A flight in the afternoon could potentially save you up to 38% on airfare.

Question 17

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

Accepted Answer

Seattle/Tacoma Intl (SEA) is the airport you will fly out of if you book a flight from Seattle to London. You should not have trouble finding flights to London from Seattle/Tacoma Intl; the airport handles an average of 18 outbound flights to London per day. You should also have plenty of airline options to choose from since 3 airlines have flights from the Seattle airport to London. It is only a 11.4 mi journey to Seattle/Tacoma Intl (SEA) from Seattle’s city center.

Question 18

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

Accepted Answer

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

Question 19

How can I find direct flights from Seattle to London?

Accepted Answer

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

Question 20

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

Accepted Answer

Yes. Cheapflights offers flight deals from Seattle to London 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 21

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

Accepted Answer

Deals for Seattle to London 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 22

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

Accepted Answer

Cheapflights simply makes it quick and affordable to book flights from Seattle to London by bringing together all flight options from hundreds of airlines and agencies online — and put it in one place for you to choose from. Plus, Cheapflights is 100% free to use for all.

Question 23

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

Accepted Answer

Users can book flights with no change fees policies with our dedicated filters. Book flights from Seattle to London flexibly with Cheapflights today.

Question 24

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

Accepted Answer

Yes, and it’s super simple to set up. Click the bell icon next to the flight deals above and provide a valid email address to enable Price Alerts. That’s it!

Round-trip from	£435
One-way from	£177
Popular in	June
Cheapest in	October
Average price	£751
Good round-trip deal	£462 or less
Good one-way deal	£363 or less

Airline	Cheapest	Average	Flexibility	On-time
Icelandair	Cheapest£353	Average£482	FlexibilityNo cancel fee	On-time76%	Search Icelandair flights
Virgin Atlantic	Cheapest£438	Average£629	FlexibilityNo cancel fee	On-time72%	Search Virgin Atlantic flights
British Airways	Cheapest£447	Average£782	FlexibilityNo cancel fee	On-time70%	Search British Airways flights

Cheap flights from Seattle to London from £177

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 27/7. Fares are subject to change and may not be available on all flights or dates of travel.

Cheapflights Tip: The best prices from Seattle/Tacoma Intl to London are usually found in October or January, booked 81 days in advance, depart on a Tuesday or Monday and return on a Tuesday

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Cheapest flights from Seattle to LondonExplore the most affordable flight options available from Seattle to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 27 6月 2025.

Explore the most affordable flight options available from Seattle to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 27 6月 2025.

Cheapflights Fare Finder

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

Best time to book a flight from Seattle to London

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

Cheapflights Insights

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

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

Use this chart to determine the optimal time to book a return flight from Seattle to London. Price data was last updated on 20 June 2025.

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

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

Find hourly flight availability from Seattle to London. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 27 6月 2025.

Weekly flight availability from Seattle to London

Explore weekly flight availability from Seattle to London. 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 27 6月 2025.

Reviews of airlines servicing London

Get insights into the airlines that provide service to London. 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 London. Reviews last updated 27 6月 2025.

Get a feel of what it's like to fly with Delta, KLM, andAustrian Airlines from Seattle to London by reading reviews from past customers. Users have also rated airlines 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 Seattle to London. 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 from for flights from Seattle to London?

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

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

What are the most popular routes from Seattle to London?

What are the most reliable airlines from Seattle to London?

What are the cheapest flights from Seattle to London?

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

How can I find direct flights from Seattle to London?

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

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

Travelling to a place near Seattle?

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Alternative routes for Seattle to London

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Top 3 airlines flying from Seattle to London

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

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

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

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

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Cheapest flights from Seattle to London
Explore the most affordable flight options available from Seattle to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 27 6月 2025.