Cheap flights from Washington to London from £83

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 £242. The month of August is another great option to travel to London Heathrow Airport, with average flight prices from State of Washington averaging around £315.

On average, the least expensive day to fly to London Heathrow Airport from State of Washington is on a Thursday. momondo users have found tickets for Thursday departures for as low as £533. 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 £682.

According to our data, the cheapest time of day to fly to London Heathrow Airport is at midday. momondo users have found flights departing from State of Washington to London Heathrow Airport at midday for as low as £614. 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 evening when prices are £638 on average. Flights to London Heathrow Airport from State of Washington in the evening 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 £629 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 £547 on momondo.

There are 3 cabin classes available to choose from on State of Washington to London Heathrow Airport flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

The number of flights available between State of Washington and London Heathrow Airport is 27 per day as of June 2026. The most frequent departure time is 13:00, with 70% of daily flights leaving in the evening.

As of June 2026, 193 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 16% of weekly flights taking off on this day.