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

Currently, February is the cheapest month in which you can book a flight from Seattle to Northern Ireland (average of $657). Flying from Seattle to Northern Ireland in June is currently the most expensive (average of $1,189). 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.

In terms of precipitation, rainfall in Northern Ireland ranges from 2.0 - 3.5 inches per month. October is typically the wettest month, when rainfall can reach 3.5 in. April is typically the driest time to visit Northern Ireland when rainfall is around 2.0 in.

If weather is an important factor for your trip to Northern Ireland, 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 60.8 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 41.0 F).

What is the cheapest month to fly from Seattle to Northern Ireland?

Our data shows that March tends to be the cheapest month to fly to Northern Ireland from Seattle. Users have commonly found prices around $946 for the month, but tickets can be as low as $707. Due to multiple factors, prepare for potentially higher prices in August.

What airport do you fly from for flights from Seattle to Northern Ireland?

Seattle/Tacoma Intl (SEA), located 11.4 mi from the city center, is the airport you fly out of when you book flights from Seattle to Northern Ireland.

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

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

How can I find direct flights from Seattle to Northern Ireland?

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

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

Yes. Cheapflights offers flight deals from Seattle to Northern Ireland by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

$254+ Flights from Seattle to Northern Ireland

Home Search by date Vacation packages Hotels Flight deals Car rental Travel tips & news

Find cheap flights from Seattle to Northern Ireland with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from Seattle to Northern Ireland

Round-trip from	$677 (Trip.com)
Popular in	August
Cheapest in	March
Average price	$1,145

From Seattle/Tacoma Intl to Northern Ireland

Search Deals

Highest demand for flights based on searches. 19% potential increase in price ($228 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 5% potential price decrease ($50 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in July 2025

Search Deals

Find flight deals from Seattle to Northern Ireland

Cheapest flights from Seattle to Northern Ireland
Explore the most affordable flight options available from Seattle to Northern Ireland. Find the lowest fares from popular airlines and budget airlines, with prices last updated on julio 3, 2025.

sáb. 9/67:00 pmSEA - BFS

2 stops18h 30mMultiple Airlines

dom. 9/217:00 amBFS - SEA

2 stops42h 50mMultiple Airlines

Deal found 7/2

$677

sáb. 9/63:45 pmSEA - BHD

2 stops16h 10mMultiple Airlines

dom. 9/217:05 amBHD - SEA

2 stops45h 35mMultiple Airlines

Deal found 7/2

$684

mié. 10/13:00 pmSEA - BHD

2 stops16h 35mBritish Airways

mié. 10/226:50 amBHD - SEA

2 stops21h 56mBritish Airways

Deal found 7/2

$770

dom. 8/177:35 pmSEA - BHD

2 stops30h 15mAer Lingus

dom. 8/244:55 pmBHD - SEA

2 stops32h 55mAer Lingus

Deal found 7/3

$827

mié. 12/33:00 pmSEA - BHD

1 stop22h 00mDelta

dom. 12/76:30 amBHD - SEA

1 stop13h 20mDelta

Deal found 7/2

$859

dom. 8/171:55 pmSEA - BHD

1 stop19h 00mKLM

dom. 8/245:25 pmBHD - SEA

1 stop26h 10mKLM

Deal found 7/3

$860

mar. 12/21:23 amSEA - BHD

2 stops28h 52mAmerican Airlines

dom. 12/79:10 amBHD - SEA

2 stops17h 10mAmerican Airlines

Deal found 7/2

$989

Best flights from Seattle to Northern Ireland
Discover carefully curated flight deals from Seattle to Northern Ireland that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated julio 3, 2025.

sáb. 9/67:00 pmSEA - BFS

2 stops18h 30mMultiple Airlines

dom. 9/217:00 amBFS - SEA

2 stops42h 50mMultiple Airlines

Deal found 7/2

$677

mié. 10/13:00 pmSEA - BHD

2 stops16h 35mBritish Airways

mié. 10/226:50 amBHD - SEA

2 stops21h 56mBritish Airways

Deal found 7/2

$770

dom. 8/177:35 pmSEA - BHD

2 stops30h 15mAer Lingus

dom. 8/244:55 pmBHD - SEA

2 stops32h 55mAer Lingus

Deal found 7/3

$827

dom. 8/171:55 pmSEA - BHD

1 stop19h 00mKLM

dom. 8/245:25 pmBHD - SEA

1 stop26h 10mKLM

Deal found 7/3

$860

dom. 8/179:40 amSEA - BHD

2 stops23h 15mDelta

dom. 8/246:30 amBHD - SEA

1 stop17h 25mDelta

Deal found 7/3

$864

sáb. 9/63:45 pmSEA - BHD

2 stops16h 10mMultiple Airlines

dom. 9/217:05 amBHD - SEA

2 stops45h 35mMultiple Airlines

Deal found 7/2

$684

Last-minute flights from Seattle to Northern Ireland
Discover last-minute flight deals from Seattle to Northern Ireland. Data last updated julio 3, 2025 and is based on user searches.

vie. 7/181:30 pmSEA - BHD

1 stop11h 55mBritish Airways

vie. 7/256:35 amBHD - SEA

2 stops26h 08mBritish Airways

Deal found 7/1

$1,057

sáb. 8/167:00 pmSEA - BFS

2 stops19h 25mMultiple Airlines

sáb. 8/239:40 amBFS - SEA

2 stops33h 45mMultiple Airlines

Deal found 7/2

$855

dom. 8/177:35 pmSEA - BHD

2 stops30h 15mAer Lingus

dom. 8/244:55 pmBHD - SEA

2 stops32h 55mAer Lingus

Deal found 7/3

$827

dom. 8/171:55 pmSEA - BHD

1 stop19h 00mKLM

dom. 8/245:25 pmBHD - SEA

1 stop26h 10mKLM

Deal found 7/3

$860

dom. 8/179:40 amSEA - BHD

2 stops23h 15mDelta

dom. 8/246:30 amBHD - SEA

1 stop17h 25mDelta

Deal found 7/3

$864

dom. 8/177:20 amSEA - BHD

3 stops23h 10mMultiple Airlines

dom. 8/243:15 pmBHD - SEA

3 stops28h 40mMultiple Airlines

Deal found 7/3

$964

Cheapflights Fare Finder

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

Fly from

Fly to

Route

Depart

Return

Price

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

sáb. 9/6

7:00 pm-9:30 pm

2 stops18h 30m

Belfast Intl

dom. 9/21

7:00 am-5:50 pm

2 stops42h 50m

$677

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

sáb. 9/6

3:45 pm-3:55 pm

2 stops16h 10m

Belfast City

dom. 9/21

7:05 am-8:40 pm

2 stops45h 35m

$684

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

mié. 10/1

3:00 pm-3:35 pm

2 stops16h 35m

Belfast City

mié. 10/22

6:50 am-8:46 pm

2 stops21h 56m

$770

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

dom. 8/17

7:35 pm-9:50 am

2 stops30h 15m

Belfast City

dom. 8/24

4:55 pm-5:50 pm

2 stops32h 55m

$827

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

mié. 12/3

3:00 pm-9:00 pm

1 stop22h 00m

Belfast City

dom. 12/7

6:30 am-11:50 am

1 stop13h 20m

$859

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

dom. 8/17

1:55 pm-4:55 pm

1 stop19h 00m

Belfast City

dom. 8/24

5:25 pm-11:35 am

1 stop26h 10m

$860

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

mar. 12/2

1:23 am-2:15 pm

2 stops28h 52m

Belfast City

dom. 12/7

9:10 am-6:20 pm

2 stops17h 10m

$989

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

mié. 10/15

7:00 pm-8:35 pm

2 stops17h 35m

$254

SeattleBelfast

SEA - BHD

SEABHD

Seattle/Tacoma Intl

mié. 10/15

1:30 pm-11:55 am

1 stop14h 25m

$432

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/3

Best time to book a flight from Seattle to Northern Ireland

Have a flexible travel schedule? Discover the best time to fly to Northern Ireland from Seattle 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 Seattle to Northern Ireland

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

When flying from Seattle to Northern Ireland, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

Reviews of airlines servicing Northern Ireland

Read reviews from past customers who have flown Delta, KLM, and Aer Lingus from Seattle to Northern Ireland. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.

Delta

8.0

Very good

7,982 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Delta

8.0

Very good

7,982 reviews

Delta

8.0

Very good

7,982 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

KLM

7.8

Good

1,367 reviews

Delta

8.0

Very good

7,982 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Aer Lingus

7.1

Good

1,144 reviews

Delta

8.0

Very good

7,982 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

British Airways

6.6

Okay

7,093 reviews

Delta

8.0

Very good

7,982 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Related info for your journey

What airport do you fly from for flights from Seattle to Northern Ireland?
Seattle/Tacoma Intl (SEA), located 11.4 mi from the city center, is the airport you fly out of when you book flights from Seattle to Northern Ireland.
Can I find deals for flights from Seattle to Northern Ireland that include hotel bookings?
Yes. In addition to deals on Seattle to Northern Ireland flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Seattle to Northern Ireland?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Northern Ireland.
Can I find deals for business class flights from Seattle to Northern Ireland?
Yes. Cheapflights offers flight deals from Seattle to Northern Ireland 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 Seattle to Northern Ireland?
Currently, February is the cheapest month in which you can book a flight from Seattle to Northern Ireland (average of $657). Flying from Seattle to Northern Ireland in June is currently the most expensive (average of $1,189). 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

Browse thousands of different options on Cheapflights for your next trip

Alternative routes for Seattle to Northern Ireland

Seattle to Heathrow flights

Seattle to Gatwick flights

Seattle to London City flights

Portland to Heathrow flights

Seattle to Luton flights

Seattle to Stansted flights

Portland to Gatwick flights

Seattle to Edinburgh flights

Portland to London City flights

Seattle to Glasgow Intl flights

Portland to Edinburgh flights

Seattle to Manchester flights

Spokane to Heathrow flights

Portland to Glasgow Intl flights

Spokane to Gatwick flights

Portland to Stansted flights

Portland to Luton flights

Portland to Manchester flights

Seattle to Inverness flights

Portland to Inverness flights

Spokane to Edinburgh flights

Spokane to London City flights

Seattle to Belfast Intl flights

Portland to Bristol flights

Seattle to Southampton flights

Portland to Aberdeen flights

Seattle to Birmingham flights

Portland to Belfast Intl flights

Pasco to Heathrow flights

Seattle to Bristol flights

Spokane to Glasgow Intl flights

Portland to Leeds flights

Portland to Belfast City flights

Seattle to Belfast City flights

Seattle to Southend flights

Seattle to Newcastle upon Tyne flights

Spokane to Manchester flights

Seattle to Cardiff flights

Bellingham to Heathrow flights

Walla Walla to Heathrow flights

Seattle to Aberdeen flights

Seattle to Darlington flights

Seattle to Liverpool flights

Portland to Sumburgh/Shetland flights

Portland to Southend flights

Seattle to Leeds flights

Seattle to Newquay flights

Seattle to Grimsby flights

Spokane to Southampton flights

Top airline flying from Seattle to Northern Ireland

Airline	Cheapest	Average	Flexibility	On-time
British Airways	Cheapest$519	Average$866	FlexibilityNo cancel fee	On-time70%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.

$254+ Cheap flights from Seattle (SEA) to Northern Ireland

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 10/15. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Seattle to Northern Ireland with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheap flight deals from Seattle to Northern Ireland

Keep the following information in mind while searching for Seattle to Northern Ireland flight deals. Data was last updated julio 3, 2025.

Round-trip from

Popular in

Cheapest in

Average price

Find flight deals from Seattle to Northern Ireland

Cheapest flights from Seattle to Northern IrelandExplore the most affordable flight options available from Seattle to Northern Ireland. Find the lowest fares from popular airlines and budget airlines, with prices last updated on julio 3, 2025.

Explore the most affordable flight options available from Seattle to Northern Ireland. Find the lowest fares from popular airlines and budget airlines, with prices last updated on julio 3, 2025.

Cheapflights Fare Finder

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

Best time to book a flight from Seattle to Northern Ireland

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

Cheapflights Insights

Everything you need to know about your flight from Seattle to Northern Ireland

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

Find hourly flight availability from Seattle to Northern Ireland. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated julio 3, 2025.

Reviews of airlines servicing Northern Ireland

Read reviews from past customers who have flown Delta, KLM, and Aer Lingus from Seattle to Northern Ireland. 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 Seattle to Northern Ireland. 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 Northern Ireland?

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

How can I find direct flights from Seattle to Northern Ireland?

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

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

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.

Alternative routes for Seattle to Northern Ireland

See prices for flight routes from nearby airports that may be better suited for you.

Top airline flying from Seattle to Northern Ireland

100% Free

Book with Flexibility

Travel Smart

Cheapest flights from Seattle to Northern Ireland
Explore the most affordable flight options available from Seattle to Northern Ireland. Find the lowest fares from popular airlines and budget airlines, with prices last updated on julio 3, 2025.