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$144+ Cheap flights from Dulles Intl (IAD) to Seattle (SEA)

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 2/20. Fares are subject to change and may not be available on all flights or dates of travel.
IAD — SEA
Jan 25 — Feb 11
Sat 1/25
Sat 2/1
1 adult, Economy
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The best prices from Washington, D.C. Dulles Intl to Seattle/Tacoma Intl are usually found in February or January, booked 40 days in advance, depart on a Tuesday or Wednesday and return on a Tuesday

Cheap flight deals from Dulles Intl to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from Dulles Intl (IAD) 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 January 20, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$276
(Trip.com)

One-way from

$144
(Alaska Airlines)

Popular in

December

Cheapest in

February

Average price

$357
Provider with most accurate pricing for Washington, D.C. Dulles Intl-Seattle/Tacoma Intl flight deals.
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Provider most trusted by Cheapflights users for Washington, D.C. Dulles Intl-Seattle/Tacoma Intl flights.
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From Washington, D.C. Dulles Intl to Seattle/Tacoma Intl
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One-way flight from Washington, D.C. Dulles Intl to Seattle/Tacoma Intl
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High demand for flights, 2% potential price rise
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Best time to find cheap flights, 2% potential price drop
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Average for round-trip flights in January 2025
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Find flight deals from Dulles Intl to Seattle

Cheapest flights from Dulles Intl to Seattle
Explore the most affordable flight options available from Dulles Intl to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 20, 2025.

This Trip.com deal was found by Cheapflights users on 1/19. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/197:00 amIAD - SEA
Nonstop5h 56mAlaska Airlines
Wed 2/269:50 amSEA - IAD
Nonstop4h 58mAlaska Airlines
Deal found 1/19$276
This Delta deal was found by Cheapflights users on 1/20. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/114:05 pmIAD - SEA
Nonstop6h 01mDelta
Wed 2/267:28 amSEA - IAD
Nonstop5h 00mDelta
Deal found 1/20$277
This United Airlines deal was found by Cheapflights users on 1/19. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/195:19 pmIAD - SEA
Nonstop6h 00mUnited Airlines
Mon 2/247:15 amSEA - IAD
1 stop10h 48mUnited Airlines
Deal found 1/19$288
This American Airlines deal was found by Cheapflights users on 1/20. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/111:52 pmIAD - SEA
2 stops12h 39mAmerican Airlines
Wed 2/2611:54 amSEA - IAD
1 stop7h 39mAmerican Airlines
Deal found 1/20$308
This Cheapflightsfares deal was found by Cheapflights users on 1/19. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/2812:40 pmIAD - SEA
1 stop7h 52mSun Country Air
Wed 7/96:40 pmSEA - IAD
1 stop14h 03mSun Country Air
Deal found 1/19$338
This Southwest deal was found by Cheapflights users on 1/19. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/186:55 amIAD - SEA
2 stops18h 35mSouthwest
Tue 2/2512:20 pmSEA - IAD
1 stop7h 45mSouthwest
Deal found 1/19$352
This eDestinos deal was found by Cheapflights users on 1/20. 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 eDestinos is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/288:46 pmIAD - SEA
2 stops39h 34mFrontier
Sat 3/812:03 pmSEA - IAD
2 stops22h 11mFrontier
Deal found 1/20$388
This Orbitz deal was found by Cheapflights users on 1/19. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/2612:40 pmIAD - SEA
1 stop13h 10mMultiple Airlines
Thu 8/79:55 pmSEA - IAD
Nonstop5h 00mMultiple Airlines
Deal found 1/19$428

Find flights from Dulles Intl to Seattle within your budget

Customize your flight search to find flights from Dulles 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 January 20, 2025.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Wed 2/19

7:00 am-9:56 am

Nonstop5h 56m

Seattle/Tacoma Intl

Wed 2/26

9:50 am-5:48 pm

Nonstop4h 58m

$276

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Tue 2/11

4:05 pm-7:06 pm

Nonstop6h 01m

Seattle/Tacoma Intl

Wed 2/26

7:28 am-3:28 pm

Nonstop5h 00m

$277

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Wed 2/19

5:19 pm-8:19 pm

Nonstop6h 00m

Seattle/Tacoma Intl

Mon 2/24

7:15 am-9:03 pm

1 stop10h 48m

$288

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Tue 2/11

1:52 pm-11:31 pm

2 stops12h 39m

Seattle/Tacoma Intl

Wed 2/26

11:54 am-10:33 pm

1 stop7h 39m

$308

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Sat 6/28

12:40 pm-5:32 pm

1 stop7h 52m

Seattle/Tacoma Intl

Wed 7/9

6:40 pm-11:43 am

1 stop14h 03m

$338

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Tue 2/18

6:55 am-10:30 pm

2 stops18h 35m

Seattle/Tacoma Intl

Tue 2/25

12:20 pm-11:05 pm

1 stop7h 45m

$352

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Fri 2/28

8:46 pm-9:20 am

2 stops39h 34m

Seattle/Tacoma Intl

Sat 3/8

12:03 pm-1:14 pm

2 stops22h 11m

$388

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Thu 7/17

12:40 pm-10:50 pm

1 stop13h 10m

Seattle/Tacoma Intl

Mon 7/21

9:55 pm-5:55 am

Nonstop5h 00m

$428

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Thu 2/20

5:19 pm-8:19 pm

Nonstop6h 00m

$144

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Thu 4/3

11:05 am-10:51 pm

1 stop14h 46m

$145

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/19

Showing 1-10 of 15 results
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Compare providers for flights from Dulles Intl to Seattle

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Dulles Intl to Seattle in January.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*1 star
CheapflightsfaresPrice Accuracy3 starsTrust Score*1 star
CheapTicketsDealPrice Accuracy3 starsTrust Score*3 stars
PricelinePrice Accuracy2 starsTrust Score*3 stars
AranGrantPrice Accuracy3 starsTrust Score*3 stars
CheapOairPrice Accuracy2 starsTrust Score*2 stars
Kiwi.comPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-Seattle flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Washington, D.C. Dulles Intl Airport-Seattle flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Washington, D.C. Dulles Intl Airport-Seattle flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-Seattle flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Washington, D.C. Dulles Intl Airport-Seattle flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Dulles Intl to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Dulles 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.

Travel insights for flights from Dulles Intl to Seattle

Get recent, data-driven insights about flights from Dulles Intl to Seattle including ideal travel times, pricing trends, and more.

How far ahead should I book a flight from Washington, D.C. Dulles Intl Airport to Seattle?

Use this chart to determine the optimal time to book a round-trip flight from Dulles Intl to Seattle. Price data was last updated on January 17, 2025.

The price you pay for your flight from Washington, D.C. Dulles Intl Airport to Seattle may vary depending on when you book. For the best chance of a lower fare, look to book 40 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

What is the cheapest month to book a flight from Washington, D.C. Dulles Intl Airport to Seattle?

Currently, January is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Seattle (average of $238). Flying from Washington, D.C. Dulles 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.

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

Find hourly flight availability from Dulles Intl to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated January 20, 2025.

One of the essential ways to save on airfare from Washington, D.C. Dulles Intl Airport to Seattle is to remain as flexible as possible. Flights that are in the morning tend to be the most expensive. A flight at noon could potentially save you up to 25% on airfare.

What is the cheapest day to fly from Washington, D.C. Dulles Intl Airport to Seattle?

Use this chart to determine the cheapest time to fly round-trip from Dulles Intl to Seattle. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Washington, D.C. Dulles Intl Airport to Seattle flight should consider departing on Saturday at noon when fares are most often at their lowest. Wednesday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Washington, D.C. Dulles Intl Airport to Seattle

Explore weekly flight availability from Dulles Intl to Seattle. 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 January 20, 2025.

The most flights from IAD to SEA are scheduled on a Thursday (17 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (13 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 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).

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. 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 Seattle. Reviews last updated January 20, 2025.
Get a feel of what it's like to fly with Alaska Airlines, United Airlines and Delta from Washington, D.C. to Seattle by reading reviews from past customers. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Overall

8.1

Entertainment

7.7

Boarding

8.2

Comfort

8.1

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

Southwest
8.1
Very good
4,659 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Overall

8.1

Entertainment

7.7

Boarding

8.2

Comfort

8.1

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

Alaska Airlines
8.0
Very good
9,696 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Overall

8.1

Entertainment

7.7

Boarding

8.2

Comfort

8.1

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

Delta
8.0
Very good
8,521 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Overall

8.1

Entertainment

7.7

Boarding

8.2

Comfort

8.1

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

United Airlines
7.4
Good
8,982 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Overall

8.1

Entertainment

7.7

Boarding

8.2

Comfort

8.1

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

American Airlines
7.2
Good
10,000 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Overall

8.1

Entertainment

7.7

Boarding

8.2

Comfort

8.1

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

Related info for your journey

Find useful and relevant information for your journey from Dulles 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 Washington, D.C. Dulles Intl?

    Seattle/Tacoma Intl (SEA), located 11.4 mi from the city center, is the airport you fly into when you book flights from Washington, D.C. Dulles Intl to Seattle. 6 airlines have flights to Seattle/Tacoma Intl from Washington, D.C. Dulles Intl on a regular basis. Booking flights from Washington, D.C. Dulles Intl to Seattle/Tacoma Intl should not be difficult; the airport handles an average of 14 inbound flights from Washington, D.C. Dulles Intl per day.

  • What are the cheapest airlines flying from Washington, D.C. Dulles Intl Airport to Seattle round-trip?

    Cheapflights users have booked flights from Washington, D.C. Dulles Intl Airport to Seattle round-trip from $276. Other airlines that can offer you cheap pricing are Delta, from $277, and United Airlines, from $288. Alaska Airlines is currently priced 32% below the average price you’ll pay for this route.

  • What are the cheapest airlines to fly from Washington, D.C. Dulles Intl Airport to Seattle one-way?

    To fly one-way, consider booking your trip with Alaska Airlines, which is currently one of the cheapest options available, starting at $144. Sun Country Air flights start at $145 while deals on Delta start at $147 one-way.

  • What are the most reliable airlines from Washington, D.C. Dulles Intl Airport to Seattle?

    The top 3 most reliable airlines when flying from Washington, D.C. Dulles Intl Airport to Seattle are Air Tahiti Nui (93%), Hawaiian Airlines (90%) and Qatar Airways (89%).

  • What are the cheapest flights from Washington, D.C. Dulles Intl Airport to Seattle?

    The cheapest flight price from Washington, D.C. Dulles Intl Airport to Seattle is $143. On average you can expect to pay $1,049. The most popular route, (Washington, D.C. Dulles Intl - Seattle/Tacoma Intl), can usually be booked for $277.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Dulles 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 Washington, D.C. Dulles Intl Airport to Seattle?

    Currently, January is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Seattle (average of $238). Flying from Washington, D.C. Dulles 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 Washington, D.C. Dulles Intl Airport?

Book flights to Washington, D.C. Dulles Intl Airport if you plan to visit one of these locations
SeaTac
Tukwila
Renton
Tacoma
Lacey
Federal Way
Ocean Shores
Leavenworth
Olympia
Marysville
Centralia
Cle Elum
Mukilteo
Aberdeen
Lakewood
Issaquah
Shoreline
Lynnwood
Shelton
Silverdale

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Alternative routes for Dulles Intl to Seattle

See prices for flight routes from nearby airports that may be better suited for you.
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Top 5 airlines flying from Dulles Intl to Seattle

Discover the top 5 airlines that operate flights from Dulles Intl to Seattle. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated January 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
Sun Country AirCheapest$144Average$360FlexibilityNo cancel feeOn-time83%
DeltaCheapest$185Average$396FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$227Average$427FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$254Average$409FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$273Average$467FlexibilityNo cancel feeOn-time69%
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