Cheap flights from London to Seattle from $732

The month of February is, on average, the cheapest month to fly to Seattle from London, with most prices found around $895. If you are unable to visit Seattle during the month of February, then departing from London during the month January is also very affordable. Most momondo users find prices during this month for around $921.

The cheapest day to depart from London to Seattle is on a Monday. Travellers who choose to depart for Seattle on a Monday will often find tickets for as low as $1,008. When flying out on a Thursday, the most expensive travel day of the week, you can expect to see flight prices from London to Seattle for around $1,588.

According to our data, the cheapest time of day to fly to Seattle is in the afternoon. momondo users have found flights departing from London to Seattle in the afternoon for as low as $1,541. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. In contrast, the most expensive time of day to depart to Seattle is in the morning when prices are around $1,577.

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

You are more likely to see cheaper flights to Seattle from London when booking weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around $1,117 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from London for as low as $1,036 on momondo.

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

Historically, on average around 12% of flights between London and Seattle have experienced a delay on any given week. The average delay length over the past 12 months has been 134 minutes.

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

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

According to our data, Delta have had the fewest delays on this route over the last 12 months, with about 5% of their flights experiencing any sort of delay.

As of October 2026, there are 8 flights per day flying from London to Seattle. The most common time of day flights depart is 17:00, with 54% of flights taking off in the afternoon.

As of October 2026, 58 flights take off from London and land in Seattle each week. The most common flight departure day for this route is Sun, with 22% of weekly flights taking off on this day.