Can I get a flight from London Heathrow Airport to Seattle on Finnair for under £604?

London Heathrow Airport to Seattle flights on Finnair are currently available under £604. 7 flights have been found by Cheapflights users under that amount. To find flights for your dates, click here.

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

Currently, the most affordable month to book a Finnair flight from London Heathrow Airport to Seattle in January, with an average price of £448. Conversely, traveling with Finnair from London Heathrow Airport to Seattle in May will be the most expensive, with an average cost of £875. Various factors influence flight prices, so comparing airlines, departure airports, and times can help reduce costs.

Weekly Finnair flight availability from London Heathrow Airport to Seattle

The most Finnair flights from LHR to SEA are scheduled on a Monday (2 on average). You will have fewer Finnair flight options on Monday, which is when the least amount of flights are scheduled (2 on average).

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.

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).

£394+ Finnair Flights from Heathrow to Seattle

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Cheapest Finnair flights from Heathrow to Seattle
Explore the most affordable Finnair flight options available from Heathrow to Seattle. Find the lowest fares with prices last updated on 10 October 2026.

Mon 23/1114:55 -

Nonstop9h 55m

Sun 6/1213:35 -

1 stop14h 35m

Deal found 6/10£558

Tue 10/1114:55 -

Nonstop9h 55m

Sun 28/320:20 -

Nonstop9h 25m

Deal found 8/10£598

Thu 19/1114:55 -

Nonstop9h 55m

Tue 24/1110:27 -

1 stop36h 23m

Deal found 9/10£601

Can I get a flight from London Heathrow Airport to Seattle on Finnair for under £604?
London Heathrow Airport to Seattle flights on Finnair are currently available under £604. 7 flights have been found by Cheapflights users under that amount. To find flights for your dates, click here.

Finnair flights from Heathrow to Seattle in 2026

One-way from	£394
Return from	£558
Popular in	July
Cheapest in	January
Average price (all airlines)	£546

Finnair
21/1-31/12
Nonstop
10h 00m total
London to Seattle

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Finnair
23/11-6/12
1 total stop
24h 30m total
London to Seattle

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Highest demand for flights from London Heathrow to Seattle/Tacoma Intl; 7% potential price increase.

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Best time to find cheap flights from London Heathrow to Seattle/Tacoma Intl; 1% potential price drop.

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Average price for all London Heathrow to Seattle/Tacoma Intl flights (one-way and round-trip).

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Prices

Airlines

For Economy class flights, the cheapest month to fly this route is January. The most expensive months are May and March.

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.

LHR-SEA

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Finnair flights from London Heathrow Airport to Seattle (LHR - SEA)

Find Finnair flight deals from Heathrow to Seattle

Cheapest Finnair flights from Heathrow to SeattleExplore the most affordable Finnair flight options available from Heathrow to Seattle. Find the lowest fares with prices last updated on 10 October 2026.

Explore the most affordable Finnair flight options available from Heathrow to Seattle. Find the lowest fares with prices last updated on 10 October 2026.

Best Finnair flights from Heathrow to SeattleDiscover carefully curated Finnair 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 10 October 2026.

Discover carefully curated Finnair 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 10 October 2026.

Direct Finnair flights from Heathrow to SeattleExplore direct Finnair flight options from Heathrow to Seattle based on user searches, and compare prices and availability for your desired travel dates. Data last updated 10 October 2026.

Explore direct Finnair flight options from Heathrow to Seattle based on user searches, and compare prices and availability for your desired travel dates. Data last updated 10 October 2026.

Last-minute Finnair flights from Heathrow to SeattleDiscover last-minute Finnair flight deals from Heathrow to Seattle. Data last updated 10 October 2026 and is based on user searches.

Discover last-minute Finnair flight deals from Heathrow to Seattle. Data last updated 10 October 2026 and is based on user searches.

One-way Finnair flights to SeattleSearch for one-way Finnair flight options to Seattle. Find affordable one-way fares based on user searches. Data last updated 10 October 2026.

Search for one-way Finnair flight options to Seattle. Find affordable one-way fares based on user searches. Data last updated 10 October 2026.

Can I get a flight from London Heathrow Airport to Seattle on Finnair for under £604?

Finnair flights from Heathrow to Seattle in 2026

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Popular in

Cheapest in

Average price (all airlines)

Which month is the cheapest to fly Economy class from London Heathrow Airport to Seattle?

For Economy class flights, the cheapest month to fly this route is January. The most expensive months are May and March.

Weekly Finnair flight availability from London Heathrow Airport to Seattle

The most Finnair flights from LHR to SEA are scheduled on a Monday (2 on average). You will have fewer Finnair flight options on Monday, which is when the least amount of flights are scheduled (2 on average).

Rainfall in Seattle by month

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.

Temperature in Seattle by month

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.

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Fly from Heathrow to Seattle on another airline

Consider alternative airlines that service the Seattle area. Flight routes are based on user searches made on Cheapflights and were last updated on 10 October 2026.

Other Finnair flights from Heathrow

Browse through other Finnair flights departing from Heathrow. Flight routes are based on user searches made on Cheapflights and were last updated on 10 October 2026.

Complete your trip

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

Other airlines servicing Heathrow and Seattle

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Other popular destinations in North America

If Seattle is not for you, choose from these other destinations located in North America. Flight routes are based on user searches made on Cheapflights and were last updated on 10 October 2026.

Popular flights with Finnair

Browse through some of the most popular routes that Finnair offers at this time. Flights are based on user searches made on Cheapflights and were last updated on 10 October 2026.

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Cheapest Finnair flights from Heathrow to Seattle
Explore the most affordable Finnair flight options available from Heathrow to Seattle. Find the lowest fares with prices last updated on 10 October 2026.

Best Finnair flights from Heathrow to Seattle
Discover carefully curated Finnair 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 10 October 2026.

Direct Finnair flights from Heathrow to Seattle
Explore direct Finnair flight options from Heathrow to Seattle based on user searches, and compare prices and availability for your desired travel dates. Data last updated 10 October 2026.

Last-minute Finnair flights from Heathrow to Seattle
Discover last-minute Finnair flight deals from Heathrow to Seattle. Data last updated 10 October 2026 and is based on user searches.

One-way Finnair flights to Seattle
Search for one-way Finnair flight options to Seattle. Find affordable one-way fares based on user searches. Data last updated 10 October 2026.