Cheap flights from Seattle to District of Columbia from $121

In general, January is the cheapest month to fly from Seattle to District of Columbia. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $307. If you don’t want to visit District of Columbia in January, then you should wait until July to fly from Seattle, when ticket prices are also cheap, with an average price of $341.

The cheapest day to depart on your flight to District of Columbia is on a Thursday when prices can be found for as low as $412. This is often the case because there is less demand to fly during this day of the week. On the other hand, Sunday is the most expensive day to depart from Seattle because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $575.

Flying to District of Columbia from Seattle in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $327 when looking at flights departing in the afternoon. Flights to District of Columbia are more costly in the morning, with an average ticket price of $484. Departure times in the morning fall within the peak daily travel times, which is why tickets can be more expensive.

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

You are more likely to see cheaper flights to District of Columbia from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to District of Columbia for around $419 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to District of Columbia from Seattle for as low as $317 on momondo.

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

United Airlines, Southwest, and Delta are the most popular carriers operating from Seattle/Tacoma Intl to District of Columbia

Alaska Airlines, Delta and United Airlines are the top three most popular airlines that fly to District of Columbia from Seattle according to our data. Alaska Airlines is the first choice among our users, with 53% of people opting to fly with this airline when traveling to District of Columbia. Keep in mind that there are 7 different airlines that fly to District of Columbia on a routine basis, so you have a few additional options to choose from.

19 flights are operational daily from Seattle to District of Columbia as of February 2026. The most popular departure time for this route is 9:00AM, with 55% of flights per day taking off at noon.

The number of flights available between Seattle and District of Columbia is 136 per week as of February 2026. The most frequent departure day is Thu, with 18% of weekly flights leaving on this day.