Cheap flights from London Heathrow Airport to Washington, D.C. from €366

The cheapest month to fly to Washington, D.C. from London Heathrow Airport is in February. Flight prices, which tend to average around €556, are often lower during this time because this is during the off-season. If you aren’t able to travel during the month of February, then book flights to Washington, D.C. from London Heathrow Airport during September instead. Flights to Washington, D.C. in September, while not as cheap as those in February, still average around €563.

Flying to Washington, D.C. from London Heathrow Airport in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as €758 when looking at flights departing in the afternoon. If you have a flexible travel schedule, then try to avoid flying in the morning when prices are €1,555 on average. Flights to Washington, D.C. from London Heathrow Airport in the morning are generally more expensive because this time of day is more convenient for travellers’ schedules.

Fly from London Heathrow to Washington, D.C. Dulles Intl for the best London Heathrow - Washington, D.C. flight prices

You are more likely to see cheaper flights to Washington, D.C. from London Heathrow Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to Washington, D.C. for around €634 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Washington, D.C. from London Heathrow Airport for as low as €558 on momondo.

There are 3 cabin classes available to choose from on London Heathrow Airport to Washington, D.C. 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 3% on your flight if you consider stops on a London Heathrow Airport to Washington, D.C. flight.

Historically, on average around 15% of flights between London and Washington, D.C. have experienced a delay on any given week. The average delay length over the past 12 months has been 141 minutes.

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

Monday is statistically the day of the week that experiences the fewest delays on this flight route. Thursday has historically seen more delays on average compared to the rest of the week.

According to our data, United Airlines have had the fewest delays on this route over the last 12 months, with about 10% of their flights experiencing any sort of delay.

The number of flights available between London Heathrow Airport and Washington, D.C. is 25 per day as of September 2026. The most frequent departure time is 12:00, with 100% of daily flights leaving in the afternoon.

As of September 2026, 175 flights take off from London Heathrow Airport and land in Washington, D.C. each week. The most common flight departure day for this route is Wed, with 20% of weekly flights taking off on this day.