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Cheap flights from Seattle to Washington, D.C. Dulles Intl Airport from C$ 190

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 9/9. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — IAD
17 Jun — 24 Jun1
1 adult

Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl are usually found in February or September, booked 52 days in advance, depart on a Thursday or Tuesday and return on a Wednesday

Cheap flight deals from Seattle to Dulles Intl

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Dulles Intl (IAD). 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 12 June 2025.

Round-trip from

C$ 371

One-way from

C$ 190

Popular in

December

Cheapest in

February

Average price

C$ 659

Good round-trip deal

C$ 657 or less
Hawaiian Airlines
  • Hawaiian Airlines
  • 8/11-8/11
  • Nonstop
  • 10h 44m total
  • Seattle to Washington, D.C.
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United Airlines
  • United Airlines
  • 9/9
  • Nonstop
  • 5h 10m total
  • Seattle to Washington, D.C.
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Highest demand for flights based on searches. 5% potential increase in price (C$ 46 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease (C$ 21 potential savings vs. average RT price).
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Average for round-trip flights in June 2025
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Price to beat on a round-trip flight from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl.
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Find flight deals from Seattle to Dulles Intl

Cheapest flights from Seattle to Dulles Intl
Explore the most affordable flight options available from Seattle to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 12 June 2025.

Sat 8/118:55 a.m.SEA - IAD
Nonstop4h 51mHawaiian Airlines
Sat 8/116:11 p.m.IAD - SEA
Nonstop5h 53mHawaiian Airlines
Deal found 10/6C$ 371
Wed 22/103:15 p.m.SEA - IAD
Nonstop5h 00mDelta
Tue 28/107:00 a.m.IAD - SEA
Nonstop6h 05mDelta
Deal found 10/6C$ 379
Wed 12/119:25 a.m.SEA - IAD
1 stop8h 41mUnited Airlines
Sat 15/115:55 p.m.IAD - SEA
Nonstop5h 59mUnited Airlines
Deal found 11/6C$ 387
Wed 9/73:59 p.m.SEA - IAD
Nonstop5h 00mAlaska Airlines
Tue 30/96:09 p.m.IAD - SEA
Nonstop5h 42mAlaska Airlines
Deal found 11/6C$ 392
Fri 11/711:59 p.m.SEA - IAD
1 stop8h 44mSun Country Air
Sat 19/712:46 p.m.IAD - SEA
1 stop13h 01mSun Country Air
Deal found 10/6C$ 403
Wed 10/96:45 a.m.SEA - IAD
2 stops12h 20mSouthwest
Mon 15/96:50 p.m.IAD - SEA
1 stop7h 45mSouthwest
Deal found 11/6C$ 413
Mon 7/73:11 p.m.SEA - IAD
1 stop12h 23mFrontier
Mon 14/77:30 a.m.IAD - SEA
1 stop9h 36mFrontier
Deal found 9/6C$ 547
Mon 7/76:15 p.m.SEA - IAD
1 stop14h 58mMultiple Airlines
Mon 14/79:00 a.m.IAD - SEA
Nonstop5h 47mMultiple Airlines
Deal found 9/6C$ 580

Cheapflights Fare Finder

Customize your flight search to find flights from Seattle to Dulles Intl 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 629,999 searches. Data last updated 12 June 2025.
Use the filters below to find and compare flights from Seattle to Washington, D.C. Dulles Intl Airport that are best for you.

Fly from

Seattle

Fly to

Dulles Intl

Route

Depart

Return

Price

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 8/11

8:55 a.m.-4:46 p.m.

Nonstop4h 51m

Washington, D.C. Dulles Intl

Sat 8/11

6:11 p.m.-9:04 p.m.

Nonstop5h 53m

C$ 371

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 22/10

3:15 p.m.-11:15 p.m.

Nonstop5h 00m

Washington, D.C. Dulles Intl

Tue 28/10

7:00 a.m.-10:05 a.m.

Nonstop6h 05m

C$ 379

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 12/11

9:25 a.m.-9:06 p.m.

1 stop8h 41m

Washington, D.C. Dulles Intl

Sat 15/11

5:55 p.m.-8:54 p.m.

Nonstop5h 59m

C$ 387

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 9/7

3:59 p.m.-11:59 p.m.

Nonstop5h 00m

Washington, D.C. Dulles Intl

Tue 30/9

6:09 p.m.-8:51 p.m.

Nonstop5h 42m

C$ 392

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Fri 11/7

11:59 p.m.-11:43 a.m.

1 stop8h 44m

Washington, D.C. Dulles Intl

Sat 19/7

12:46 p.m.-10:47 p.m.

1 stop13h 01m

C$ 403

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 10/9

6:45 a.m.-10:05 p.m.

2 stops12h 20m

Washington, D.C. Dulles Intl

Mon 15/9

6:50 p.m.-11:35 p.m.

1 stop7h 45m

C$ 413

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Mon 7/7

3:11 p.m.-6:34 a.m.

1 stop12h 23m

Washington, D.C. Dulles Intl

Mon 14/7

7:30 a.m.-2:06 p.m.

1 stop9h 36m

C$ 547

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Mon 7/7

6:15 p.m.-12:13 p.m.

1 stop14h 58m

Washington, D.C. Dulles Intl

Mon 14/7

9:00 a.m.-11:47 a.m.

Nonstop5h 47m

C$ 580

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 9/9

8:00 a.m.-4:10 p.m.

Nonstop5h 10m

C$ 190

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 29/7

11:30 p.m.-7:27 a.m.

Nonstop4h 57m

C$ 193

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/6

Showing 1-10 of 15 results
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Best time to book a flight from Seattle to Dulles Intl

Have a flexible travel schedule? Discover the best time to fly to Dulles Intl 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 Washington, D.C. Dulles Intl Airport

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

Use this chart to determine the optimal time to book a round-trip flight from Seattle to Dulles Intl. Price data was last updated on 9 June 2025.

Booking 52 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to Washington, D.C. Dulles Intl Airport. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, February is the cheapest month in which you can book a flight from Seattle to Washington, D.C. Dulles Intl Airport (average of C$ 256). Flying from Seattle to Washington, D.C. Dulles Intl Airport in October is currently the most expensive (average of C$ 352). 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 SEA to IAD?

Find hourly flight availability from Seattle to Dulles Intl. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 12 June 2025.

A simple way to save on the total cost of your ticket is to fly from Seattle to Washington, D.C. Dulles Intl Airport in the afternoon. If you’re flexible enough to do this you can expect to save up to 72% on your trip compared to booking a flight at noon.

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

Explore weekly flight availability from Seattle to Dulles Intl. 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 12 June 2025.

The most flights from SEA to IAD are scheduled on a Wednesday (31 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (6 on average).

Rainfall in Dulles Intl by month

Plan your trip to Dulles Intl by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Washington, D.C. Dulles Intl Airport ranges from 66.0 - 102.0 mm per month. May is typically the wettest month, when rainfall can reach 102.0 mm. February is typically the driest time to visit Washington, D.C. Dulles Intl Airport when rainfall is around 66.0 mm.

Temperature in Dulles Intl by month

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

If weather is an important factor for your trip to Washington, D.C. Dulles Intl Airport, 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 27.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 2.0 C).

Reviews of airlines servicing Dulles Intl

Get insights into the airlines that provide service to Dulles Intl. 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 Dulles Intl. Reviews last updated 12 June 2025.
Read reviews from past customers who have flown Alaska Airlines, Southwest and Delta from Seattle to Washington, D.C.. 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.
Alaska Airlines
8.0
Very good
10,000 reviews
Check prices

Overall

8.0

Entertainment

7.1

Comfort

7.8

Food

7.1

Boarding

8.1

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2024

SEA - LAS

Seats were not that comfy especially for someone with big hips 😥
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews
Check prices

Overall

8.0

Entertainment

7.1

Comfort

7.8

Food

7.1

Boarding

8.1

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2024

SEA - LAS

Seats were not that comfy especially for someone with big hips 😥
Southwest
8.0
Very good
4,287 reviews
Alaska Airlines
8.0
Very good
10,000 reviews
Check prices

Overall

8.0

Entertainment

7.1

Comfort

7.8

Food

7.1

Boarding

8.1

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2024

SEA - LAS

Seats were not that comfy especially for someone with big hips 😥
Delta
8.0
Very good
7,946 reviews
Alaska Airlines
8.0
Very good
10,000 reviews
Check prices

Overall

8.0

Entertainment

7.1

Comfort

7.8

Food

7.1

Boarding

8.1

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2024

SEA - LAS

Seats were not that comfy especially for someone with big hips 😥
Hawaiian Airlines
7.9
Good
2,494 reviews
Alaska Airlines
8.0
Very good
10,000 reviews
Check prices

Overall

8.0

Entertainment

7.1

Comfort

7.8

Food

7.1

Boarding

8.1

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2024

SEA - LAS

Seats were not that comfy especially for someone with big hips 😥
United Airlines
7.4
Good
8,790 reviews
Alaska Airlines
8.0
Very good
10,000 reviews
Check prices

Overall

8.0

Entertainment

7.1

Comfort

7.8

Food

7.1

Boarding

8.1

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Anonymous,Aug 2024

SEA - LAS

Seats were not that comfy especially for someone with big hips 😥

Related info for your journey

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

    If you book a flight to Washington, D.C. Dulles Intl from Seattle, you will be flying from Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 18.4 km from the centre of Seattle. There are 16 flights from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl per day from 1 airline.

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

    Our cheapest airline available from Seattle to Washington, D.C. Dulles Intl Airport is Hawaiian Airlines. Our recent data shows that you can find tickets from as low as C$ 371 on this airline. Additional options worth looking into are Delta and United Airlines, starting at C$ 379 and C$ 387 round-trip. Hawaiian Airlines is 32% cheaper than the average price of flights available within the next 90 days to this destination.

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

    The cheapest airline one-way is United Airlines, with whom users have recently found tickets for as low as C$ 190. However, be on the lookout for offers from Hawaiian Airlines and Sun Country Air, as they are both options that can get you from Seattle to Washington, D.C. Dulles Intl Airport for a low price.

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

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Seattle to Washington, D.C. Dulles Intl Airport on time: Avianca (92%), Copa Airlines (87%), Lufthansa (85%).

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

    While on average a flight from Seattle to Washington, D.C. Dulles Intl Airport is generally C$ 1,176, our data shows the cheapest flight currently is C$ 657. When looking at the most popular route, (Seattle/Tacoma Intl - Washington, D.C. Dulles Intl), you can expect to pay C$ 420 for that flight.

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

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

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

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

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

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

    Currently, February is the cheapest month in which you can book a flight from Seattle to Washington, D.C. Dulles Intl Airport (average of C$ 256). Flying from Seattle to Washington, D.C. Dulles Intl Airport in October is currently the most expensive (average of C$ 352). 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

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Alternative routes for Seattle to Dulles Intl

See prices for flight routes from nearby airports that may be better suited for you.
Seattle to Reagan-National flights

Top airline flying from Seattle to Dulles Intl

Discover the top airline that operate flights from Seattle to Dulles Intl. 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 629,999 searches. Data last updated 12 June 2025.
AirlineCheapestAverageFlexibilityOn-time
Alaska AirlinesCheapestC$ 261AverageC$ 440FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights

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How does Cheapflights help users find flights from Seattle to Dulles Intl?

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Can Cheapflights find flights from Seattle to Dulles Intl with no change fees?

Cheapflights does show flights with no change fees to all users. To see these options for flights from Seattle to Dulles Intl, users can toggle the no change fees filter when performing a flight search.

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