Cheap flights from Washington to London from £225

In general, January is the cheapest month to fly from State of Washington to London Heathrow Airport. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around £237. The month of February is another great option to travel to London Heathrow Airport, with average flight prices from State of Washington averaging around £316.

On average, the least expensive day to fly to London Heathrow Airport from State of Washington is on a Tuesday. momondo users have found tickets for Tuesday departures for as low as £508. However, this price may fluctuate depending on the airline, the season, and holidays. Be sure to avoid booking your departure on a Monday as prices are generally higher than usual. According to our data, the average ticket price to London Heathrow Airport on Monday is £649.

According to our data, the cheapest time of day to fly to London Heathrow Airport is in the evening. momondo users have found flights departing from State of Washington to London Heathrow Airport in the evening for as low as £541. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. If you have a flexible travel schedule, then try to avoid flying in the afternoon when prices are £610 on average. Flights to London Heathrow Airport from State of Washington in the afternoon are generally more expensive because this time of day is more convenient for travellers’ schedules.

Fly from Seattle/Tacoma Intl to London Heathrow for the best Washington - London Heathrow flight prices

You are more likely to see cheaper flights to London Heathrow Airport from State of Washington when booking weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport for around £609 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London Heathrow Airport from State of Washington for as low as £538 on momondo.

The number of flights available between State of Washington and London Heathrow Airport is 28 per day as of May 2026. The most frequent departure time is 13:00, with 71% of daily flights leaving in the evening.

As of May 2026, 200 flights take off from State of Washington and land in London Heathrow Airport each week. The most common flight departure day for this route is Tue, with 14% of weekly flights taking off on this day.