IAD - SEA

£91 Find Cheap Flights from Washington, D.C. to Seattle

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Washington, D.C. to Seattle departing on 25/4. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Seattle

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Washington, D.C. to Seattle, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Washington, D.C. to Seattle, as well as popular online travel agencies
Travellers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

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Everything you should know

Cheapest return fare
£149
Overall average: £282
Delta
Tue 28/4Fri 1/5
IAD - SEA • Direct
Cheapest one-way flight
£91
Typical prices: £117-£293
Alaska Airlines
Sat 25/4
IAD - SEA • Direct
Advice from real travellers
AI-powered summary based on content written by KAYAK users. AI can make mistakes.
Consider upgrading seats on Alaska Airlines for comfort.
Dulles offers efficient TSA lines and charging stations.
User tips
User tips
User tips
User tips
Direct flights
Every day
You can fly direct with Alaska Airlines, Delta, and United Airlines. Average duration is 5h 59m
Direct flights
Direct flights
+1
+1
Direct flights
Direct flights
+1
When to book
4 weeks
in advance
Our data shows that travellers who book at least 4 weeks in advance save around 62% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
January
Cheapest • 40% price drop
July
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
KAYAK searches hundreds of sites at once to find you the best travel deals.
We hope you love your trip to Seattle!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Washington, D.C. to Seattle (IAD-SEA)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for return flights from Washington, D.C. to Seattle that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent return flight deals from Washington, D.C. to Seattle

Tue, 28 Apr - Fri, 1 May
Delta Logo
07:00 - 09:54
IAD
-
SEA
5h 54mdirect
Delta Logo
15:59 - 23:55
SEA
-
IAD
4h 56mdirect
£149Delta
Sat, 9 May - Tue, 12 May
Southwest Logo
05:50 - 23:00
IAD
-
SEA
20h 10m
2 stops
Southwest Logo
09:20 - 23:40
SEA
-
IAD
11h 20m
2 stops
£151Southwest
Wed, 1 Apr - Wed, 15 Apr
United Airlines Logo
17:55 - 20:53
IAD
-
SEA
5h 58mdirect
United Airlines Logo
08:00 - 16:11
SEA
-
IAD
5h 11mdirect
£153United Airlines
Sun, 5 Apr - Tue, 14 Apr
Delta Logo
07:00 - 10:03
IAD
-
SEA
6h 03mdirect
Delta Logo
06:00 - 17:57
SEA
-
IAD
8h 57m
1 stop
£155Delta
Wed, 22 Apr - Tue, 28 Apr
Delta Logo
12:45 - 19:59
IAD
-
SEA
10h 14m
1 stop
Delta Logo
15:59 - 23:55
SEA
-
IAD
4h 56mdirect
£156Delta
Thu, 9 Apr - Wed, 15 Apr
Alaska Airlines Logo
07:00 - 09:53
IAD
-
SEA
5h 53mdirect
Alaska Airlines Logo
21:40 - 05:40
SEA
-
IAD
5h 00mdirect
£157Alaska Airlines
Wed, 22 Apr - Thu, 30 Apr
Southwest Logo
17:30 - 23:35
IAD
-
SEA
9h 05m
1 stop
Southwest Logo
06:30 - 00:20
SEA
-
IAD
14h 50m
2 stops
£157Southwest
Sat, 4 Apr - Fri, 10 Apr
United Airlines Logo
17:55 - 20:53
IAD
-
SEA
5h 58mdirect
United Airlines Logo
19:05 - 05:28
SEA
-
IAD
7h 23m
1 stop
£160United Airlines
Wed, 15 Apr - Sun, 19 Apr
United Airlines Logo
17:55 - 20:53
IAD
-
SEA
5h 58mdirect
United Airlines Logo
22:35 - 11:48
SEA
-
IAD
10h 13m
1 stop
£161United Airlines
Tue, 14 Apr - Tue, 21 Apr
Delta Logo
17:07 - 21:49
IAD
-
SEA
7h 42m
1 stop
Delta Logo
06:00 - 17:57
SEA
-
IAD
8h 57m
1 stop
£163Delta
Booking Insights

KAYAK’s insights & trends for Washington, D.C. to Seattle flights

Get data-powered insights and trends into flights from Washington, D.C. to Seattle to help you find the cheapest flights, the best time to fly and much more.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Washington, D.C. Dulles Intl Airport to Seattle, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Washington, D.C. Dulles Intl Airport to Seattle is January, where tickets cost £173 (return) on average. On the other hand, the most expensive months are June and March, where the average cost of round-trip tickets is £343 and £321 respectively.

Can I save money by flying with a stopover from Washington, D.C. Dulles Intl Airport to Seattle?

The average return price for all direct flights, flights with one stopover, and flights with two stopovers for the route found by users searching on KAYAK in the last 2 weeks.

Yes, flying with a stopover may cost you more time, but you can also save money on the route, with a 1 stop stopover the cheapest option at £176 on average.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Washington, D.C. Dulles Intl Airport to Seattle, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Washington, D.C. Dulles Intl Airport to Seattle, you should book around 4 weeks before departure, which saves you about 62% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 4 weeks before departure.

Good to know - Cheap tickets from Washington, D.C. to Seattle

Low seasonJanuary
Cheapest flight£91
Best time to beat the crowds (40% less expensive on average)
Most popular time to fly (11% more expensive on average)
Flight from Washington, D.C. to Seattle

When to book flights from Washington, D.C. to Seattle

Are your dates flexible? Find out the best times to travel from Washington, D.C. to Seattle based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated return price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or returns with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

Flights from Washington, D.C. to Seattle: the best tips from KAYAK users' own experiences

Insights shared by verified travellers who flew the route from Washington, D.C. to Seattle 
Verified travelerFlew with Alaska Airlines
IAD
-
SEA
Sept 2024
Pay the money if can afford to upgrade your seats
Verified travelerFlew with Alaska Airlines
IAD
-
SEA
Jul 2024
Dulles, like Seattle has a tram. That can be surprising. The TSA at Seattle is notoriously LONG, however, both times in the last year that I have flown, that has not been the case. At Dulles, the TSA lines were efficient as well. The airport interior is well marked for getting around. I did note that the garbages were full in the Southwest and Alaska areas- as we were there 6 hours and had lots of time to notice nit-picky things that nobody else would care about :). It was convenient to have a "charging station" nearby the Alaska waiting area (right across from our gate). It had 3 ports, and I noticed that as soon as I unplugged mine, it was jumped right on. Suggestion- have Dulles add a few more for passengers who need to recharge phones. Great experience, thank you.
Verified travelerFlew with Alaska Airlines
IAD
-
SEA
May 2024
Get to the airport early, especially on holidays

FAQs for booking Washington, D.C. to Seattle flights

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

    In the last 3 days, the lowest price for a flight from Washington, D.C. Dulles Intl Airport to Seattle was £91 for a one-way ticket and £149 for a return.

  • Which airports will I be using when flying from Washington, D.C. to Seattle?

    On your way to Seattle, you’ll fly out from Washington, D.C. Dulles Intl. You’ll be landing at Seattle/Tacoma Intl.

  • Which airlines offer Wi-Fi service onboard planes from Washington, D.C. to Seattle?

    Alaska Airlines, Delta, and Hawaiian Airlines offer inflight Wi-Fi service on the Washington, D.C. to Seattle flight route.

  • Which aircraft models fly most regularly from Washington, D.C. to Seattle?

    The Boeing 737 is the aircraft model that flies most regularly on the Washington, D.C. to Seattle flight route.

  • On which days can I fly direct from Washington, D.C. to Seattle?

    There are direct flights from Washington, D.C. to Seattle on a daily basis.

  • How does KAYAK find such low prices on flights from Washington, D.C. to Seattle?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Washington, D.C. to Seattle.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Washington, D.C. to Seattle?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Seattle from Washington, D.C. is likely to change within 7 days, so travellers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Washington, D.C. to Seattle?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional return ticket. You could then fly to Seattle with an airline and back to Washington, D.C. with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Washington, D.C. to Seattle?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Seattle from Washington, D.C. up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Washington, D.C. Dulles Intl Airport to Seattle

  • Looking for a cheap flight from Seattle to Washington, D.C.? 25% of our users found flights on this route for Seattle or less round-trip.

Prefer to fly direct from Washington, D.C. to Seattle?

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from Washington, D.C. Dulles Intl to Seattle/Tacoma Intl.
Find which airlines fly direct from Washington, D.C. Dulles Intl Airport to Seattle/Tacoma Intl Airport, which days they fly and book direct flights.

Direct departures

Washington, D.C. Dulles Intl to Seattle/Tacoma Intl

Monday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

Tuesday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

Wednesday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

Thursday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

Friday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

Saturday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

Sunday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

See more direct flights

Direct returns

Seattle/Tacoma Intl to Washington, D.C. Dulles Intl

Monday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

Tuesday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

Wednesday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

Thursday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

Friday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

Saturday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

Sunday

Alaska Airlines, Delta, United Airlines

Alaska Airlines, Delta, +1 more

See more direct flights

Everything you need to know for your flight from Washington, D.C. to Seattle

Information on your arrival and departure airports