Cheap flights from Washington, D.C. Dulles Intl Airport to Seattle from $143

In general, January is the cheapest month to fly from Washington, D.C. Dulles Intl Airport to Seattle. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $231. If you don’t want to visit Seattle in January, then you should wait until February to fly from Washington, D.C. Dulles Intl Airport, when ticket prices are also cheap, with an average price of $264.

On average, the least expensive day to fly to Seattle from Washington, D.C. Dulles Intl Airport is on a Tuesday. momondo users have found tickets for Tuesday departures for as low as $440. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Sunday is the most expensive day to depart from Washington, D.C. Dulles Intl Airport because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $575.

Flying to Seattle from Washington, D.C. Dulles Intl Airport at noon is the least expensive time of day to depart. momondo users have found prices as low as $445 when looking at flights departing at noon. Flights to Seattle are more costly in the evening, with an average ticket price of $497. Departure times in the evening fall within the peak daily travel times, which is why tickets can be more expensive.

Fly from Washington, D.C. Dulles Intl to Seattle/Tacoma Intl for the best Washington, D.C. Dulles Intl - Seattle/Tacoma Intl flight prices

You are more likely to see cheaper flights to Seattle from Washington, D.C. Dulles Intl Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around $378 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from Washington, D.C. Dulles Intl Airport for as low as $318 on momondo.

There are 4 cabin classes available to choose from on Washington, D.C. Dulles Intl to Seattle/Tacoma Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

You could potentially save up to 33% on your flight if you consider stops on a Washington, D.C. Dulles Intl Airport to Seattle flight.

As of April 2026, prices for Washington, D.C. Dulles Intl Airport to Seattle flights are approximately 28% cheaper when compared to flights at the same time last year.

Delta, United Airlines, and Alaska Airlines are the most popular carriers operating from Washington, D.C. Dulles Intl to Seattle/Tacoma Intl

Alaska Airlines, United Airlines and Delta are the top three most popular airlines that fly to Seattle from Washington, D.C. Dulles Intl Airport according to our data. Alaska Airlines is the first choice among our users, with 45% of people opting to fly with this airline when traveling to Seattle. Keep in mind that there are 6 different airlines that fly to Seattle on a routine basis, so you have a few additional options to choose from.

As of April 2026, 12 flights take off from Washington, D.C. Dulles Intl Airport and land in Seattle each day. The most common flight departure time for this route is 5:00PM, with 46% of daily flights taking off in the afternoon.

As of April 2026, there are 88 flights per week flying from Washington, D.C. Dulles Intl Airport to Seattle. The most common day of the week flights depart is Tue, with 24% of flights taking off on this day.