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$1,271+ Cheap flights from Belfast Intl (BFS) to Seattle (SEA)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 5/31. Fares are subject to change and may not be available on all flights or dates of travel.
BFS — SEA
Apr 22 — Apr 291
Tue 4/22
Tue 4/29
1 adult, Economy
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Cheap flight deals from Belfast Intl to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from Belfast Intl (BFS) to Seattle (SEA). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated April 17, 2025.

Round-trip from

$1,271
(Mytrip)

Popular in

July

Cheapest in

May

Average price

$690
From Belfast Intl to Seattle/Tacoma Intl
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Highest demand for flights based on searches. 18% potential increase in price ($196 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($29 potential savings vs. average RT price).
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Average for round-trip flights in April 2025
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Find flight deals from Belfast Intl to Seattle

Cheapest flights from Belfast Intl to Seattle
Explore the most affordable flight options available from Belfast Intl to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 17, 2025.

This Mytrip deal was found by Cheapflights users on 4/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/316:00 amBFS - SEA
2 stops18h 00mMultiple Airlines
Sat 6/710:00 amSEA - BFS
3 stops28h 30mMultiple Airlines
Deal found 4/16$1,271

Cheapflights Fare Finder

Customize your flight search to find flights from Belfast Intl to Seattle that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated April 17, 2025.
Use the filters below to find and compare flights from Belfast Intl Airport to Seattle that are best for you.

Fly from

Belfast Intl

Fly to

Seattle

Route

Depart

Return

Price

BelfastSeattle

BFS - SEA

BFSSEA

Belfast Intl

Sat 5/31

6:00 am-4:00 pm

2 stops18h 00m

Seattle/Tacoma Intl

Sat 6/7

10:00 am-10:30 pm

3 stops28h 30m

$1,271

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/16

Best time to book a flight from Belfast Intl to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Belfast Intl with our price prediction graph.
Estimated round-trip 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.

Cheapflights Insights

Everything you need to know about your flight from Belfast Intl Airport to Seattle

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 0.7 - 6.6 inches per month. November is typically the wettest month, when rainfall can reach 6.6 in. July is typically the driest time to visit Seattle when rainfall is around 0.7 in.

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 66.2 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 41.0 F).

Related info for your journey

Find useful and relevant information for your journey from Belfast Intl 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 Belfast Intl?

    Seattle/Tacoma Intl (SEA), located 11.4 mi from the city center, is the airport you fly into when you book flights from Belfast Intl to Seattle. 0 airlines have flights to Seattle/Tacoma Intl from Belfast Intl on a regular basis. Booking flights from Belfast Intl to Seattle/Tacoma Intl should not be difficult; the airport handles an average of 0 inbound flights from Belfast Intl per day.

  • Can I find deals for flights from Belfast Intl to Seattle that include hotel bookings?

    Yes. In addition to deals on Belfast Intl to Seattle flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Belfast Intl to Seattle?

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

  • Can I find deals for business class flights from Belfast Intl to Seattle?

    Yes. Cheapflights offers flight deals from Belfast Intl 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.

  • What is the cheapest month to book a flight from Belfast Intl Airport to Seattle?

    Currently, January is the cheapest month in which you can book a flight from Belfast Intl Airport to Seattle (average of $238). Flying from Belfast Intl Airport to Seattle in July is currently the most expensive (average of $411). 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.

See more FAQs

Traveling to a place near Belfast Intl Airport?

Book flights to Belfast Intl Airport if you plan to visit one of these locations
SeaTac
Tukwila
Tacoma
Renton
Lakewood
Ocean Shores
Lacey
Leavenworth
Federal Way
Olympia
Shoreline
Cle Elum
Centralia
Aberdeen
Kent
Lynnwood
Shelton
Silverdale
Redmond
Issaquah

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Alternative routes for Belfast Intl to Seattle

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