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Finnair flights from London to Seattle (LON - SEA)

LON — SEA
10 Aug — 17 Aug1
1 adult
1 adult, Economy, 0 bags

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Cheapest Finnair flights from London to Seattle
Explore the most affordable Finnair flight options available from London to Seattle. Find the lowest fares with prices last updated on 11 July 2026.

Fri 28/810:20
LHR
-
SEA
1 stop13h 40m
Finnair
Sun 6/913:30
SEA
-
LHR
Nonstop9h 15m
Finnair
Deal found 8/7£522
Thu 27/818:10
LHR
-
SEA
1 stop29h 50m
Finnair
Thu 10/913:30
SEA
-
LHR
Nonstop9h 15m
Finnair
Deal found 6/7£523
Mon 31/810:20
LHR
-
SEA
1 stop13h 40m
Finnair
Thu 10/920:20
SEA
-
LHR
Nonstop9h 25m
Finnair
Deal found 9/7£525

  • How do most travelers feel about Finnair?

    When planning your LON-SEA trip, keep in mind that Finnair is typically rated 7.6/10. This rating comes from 1,418 reviews by Cheapflights users who have traveled with Finnair.

  • Can I get a flight from London to Seattle on Finnair for under £671?

    Cheapflights currently has 9 LON-SEA flights for under £671. Flights to Seattle will vary based on many factors, like date and time. Click here to find the best price for your dates on Cheapflights.

Finnair flights from London to Seattle in 2026

Find detailed information about Finnair flights from London to Seattle. Explore the options provided by Finnair to plan your journey from London to Seattle. Data last updated 11 July 2026.

One-way from

£445

Return from

£508

Popular in

December

Cheapest in

February

Average price (all airlines)

£628
Finnair
  • Finnair
  • 17/9
  • 1 total stop
  • 29h 43m total
  • London to Seattle
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Finnair
  • Finnair
  • 4/9-19/9
  • 2 total stops
  • 26h 50m total
  • London to Seattle
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Highest demand for flights from London to Seattle/Tacoma Intl; 0% potential price increase.
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Best time to find cheap flights from London to Seattle/Tacoma Intl; 1% potential price drop.
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Average price for all London to Seattle/Tacoma Intl flights (one-way and round-trip).
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Which month is the cheapest to fly Economy class from London to Seattle?

For Economy class flights, the cheapest month to fly this route is June. The most expensive months are October and August.

Weekly Finnair flight availability from London to Seattle

The most Finnair flights from LON 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

Plan your trip to Seattle by taking into account the average rainfall totals 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

Plan your trip to Seattle by taking into account the average temperature totals by month.

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).

Best time to book a flight from London to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from London with our price prediction graph.
Estimated return price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

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 London 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 11 July 2026.
Virgin Atlantic flights from London to Seattle/Tacoma Intl
British Airways flights from London to Seattle/Tacoma Intl

See what others are saying about Finnair

Read reviews and see what other travellers are saying about their experiences with Finnair. Get insights from real passengers regarding the airline's services, customer satisfaction, and overall travel experience. Use these reviews to inform your decision when choosing Finnair for your next flight. Reviews last updated 11 July 2026.
Finnair
7.6
Good
1,418 reviews
Check prices
Overview

Comfort

7.4

Crew

8.2

Food

6.7

Boarding

7.7

Entertainment

6.9

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