Cheap flights from Washington, D.C. Dulles Intl Airport to Portugal from $343

The cheapest month to fly to Portugal from Washington, D.C. Dulles Intl Airport is in January. Flight prices, which tend to average around $201, are often lower during this time because this is during the off-season. If you aren’t able to travel during the month of January, then book flights to Portugal from Washington, D.C. Dulles Intl Airport during July instead. Flights to Portugal in July, while not as cheap as those in January, still average around $265.

According to our data, Monday is the cheapest day to fly to Portugal from Washington, D.C. Dulles Intl Airport. The lowest ticket price found for a Monday departure recently was $755. Keep in mind that prices can always vary depending on your route and whether or not you are flying domestic or international. The most expensive day to fly to Portugal is Friday, with ticket prices averaging around $894.

Our most recent data shows that the best time of day to fly to Portugal is in the afternoon. Flights from Washington, D.C. Dulles Intl Airport to Portugal during this time can be as low as $766. In the evening is when there is more demand to fly to Portugal, so prices are often more expensive at around $851 per ticket.

Fly from Washington, D.C. Dulles Intl to Lisbon Humberto Delgado for the best Washington, D.C. Dulles Intl - Portugal flight prices

You are more likely to see cheaper flights to Portugal from Washington, D.C. Dulles Intl Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to Portugal for around $942 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Portugal from Washington, D.C. Dulles Intl Airport for as low as $827 on momondo.

KLM, Air France, and TAP AIR PORTUGAL are the most popular carriers operating from Washington, D.C. Dulles Intl to Portugal

TAP AIR PORTUGAL, United Airlines and Lufthansa are the top three most popular airlines that fly to Portugal from Washington, D.C. Dulles Intl Airport according to our data. TAP AIR PORTUGAL is the first choice among our users, with 81% of people opting to fly with this airline when traveling to Portugal. Keep in mind that there are 12 different airlines that fly to Portugal on a routine basis, so you have a few additional options to choose from.

Historically, on average around 28% of flights between Washington, D.C. and Portugal have experienced a delay on any given week. The average delay length over the past 12 months has been 146 minutes.

Generally, flights departing in the evening tend to experience fewer delays. Flights in the morning have, in the past, seen delays more frequently in comparison.

Saturday is statistically the day of the week which experiences the fewest number of delays on this flight route. Friday has historically seen more delays on average compared to the rest of the week.

According to our data, TAP AIR PORTUGAL have had the least number of delays on this route over the last 12 months; with about 26% of their flights experiencing any sort of delay.

The number of flights available between Washington, D.C. Dulles Intl Airport and Portugal is 5 per day as of May 2026. The most frequent departure time is 10:00PM, with 89% of daily flights leaving in the evening.

As of May 2026, 37 flights take off from Washington, D.C. Dulles Intl Airport and land in Portugal each week. The most common flight departure day for this route is Thu, with 22% of weekly flights taking off on this day.