Seattle to London Flight Time & Schedules

What Is the Flight Duration Between Seattle and London?

A nonstop flight from Seattle to London generally takes around 9 hours 15 minutes to 9 hours 55 minutes. Direct services leave Seattle-Tacoma International Airport (SEA) and arrive at London Heathrow Airport (LHR).

The nonstop journey covers approximately 4,780 to 4,810 miles (about 7,700 km) across North America and the North Atlantic. British Airways, Virgin Atlantic, Delta Air Lines and Alaska Airlines currently provide nonstop flights on the SEA–LHR route.

Passengers who do not choose a direct service have a wide range of one-stop alternatives. Current routings include connections through Reykjavik, Dublin, Calgary, Vancouver, Paris, Denver and several other North American and European airports.

Some efficient one-stop journeys take approximately 12 hours 10 minutes via Reykjavik, around 12 hours 15 minutes through Calgary or Vancouver, and about 12 hours 45 minutes through Dublin. The total duration can increase considerably when an itinerary has a longer connection.

For most passengers, a nonstop Seattle-to-London flight saves several hours and removes the need to change aircraft during the journey.

How Much Time Does a Seattle to London Flight Normally Take?

Most nonstop journeys from Seattle to London are scheduled at between 9 hours 15 minutes and 9 hours 55 minutes. The exact duration depends on the airline, departure time and operating schedule.

Passengers taking a connecting flight should allow considerably longer. Some current one-stop examples include:

Via Reykjavik (KEF): around 12 hours 10 minutes to 12 hours 15 minutes
Via Calgary (YYC): around 12 hours 15 minutes
Via Vancouver (YVR): around 12 hours 15 minutes
Via Dublin (DUB): around 12 hours 45 minutes
Via Denver (DEN): around 12 hours 56 minutes
Via Paris (CDG): around 13 hours
Via Portland (PDX): around 13 hours 5 minutes or more

These figures represent some of the faster scheduled combinations. Other itineraries can take 14, 15 hours or longer when additional waiting time is involved.

The fastest way to travel between the two cities is usually a direct flight from SEA to LHR.

Current schedules place the nonstop journey at approximately 9 hours 15 minutes to 9 hours 55 minutes, depending on the particular flight. Heathrow is presently the London airport receiving regular nonstop passenger services from Seattle.

The route is approximately 4,800 miles long and crosses eight time zones before reaching the United Kingdom.

Heathrow is London's largest airport and provides onward transport towards central London as well as connections to destinations throughout the UK, Europe and other international markets.

For passengers whose main priority is reducing travel time, SEA–LHR is therefore generally more convenient than flying through another hub.

Reykjavik's Keflavik International Airport (KEF) is one of the quicker connection points between Seattle and London.

Some SEA–KEF–LHR itineraries take approximately 12 hours 10 minutes to 12 hours 15 minutes from departure in Seattle to arrival in London. Icelandair is among the airlines offering this type of routing.

This adds roughly two and a half to three hours compared with many nonstop schedules, although the exact difference depends on the connection available that day.

Travellers should check the entire itinerary because different Reykjavik connections can have substantially different layover lengths.

There are several other relatively efficient ways to reach London with one connection.

A journey through Dublin Airport (DUB) can take around 12 hours 45 minutes on faster Aer Lingus combinations.

Some itineraries via Calgary International Airport (YYC) or Vancouver International Airport (YVR) can take approximately 12 hours 15 minutes.

These routings may be useful when the nonstop departure time does not fit a passenger's plans or when a particular airline itinerary is preferred.

Longer connections can significantly increase the overall trip, so passengers should compare the elapsed journey rather than looking only at the individual flight sectors.

Seattle to London Flight Time by Route

Departure Airport	Arrival Airport	Route Code	Approximate Flight Duration
Seattle-Tacoma International Airport (SEA)	London Heathrow Airport (LHR)	SEA–LHR	Around 9 hrs 15 mins–9 hrs 55 mins nonstop
Seattle-Tacoma International Airport (SEA)	London Heathrow Airport (LHR)	SEA–KEF–LHR	Around 12 hrs 10 mins–12 hrs 15 mins with one stop
Seattle-Tacoma International Airport (SEA)	London Heathrow Airport (LHR)	SEA–YYC–LHR	Around 12 hrs 15 mins with one stop
Seattle-Tacoma International Airport (SEA)	London Heathrow Airport (LHR)	SEA–YVR–LHR	Around 12 hrs 15 mins with one stop
Seattle-Tacoma International Airport (SEA)	London Heathrow Airport (LHR)	SEA–DUB–LHR	Around 12 hrs 45 mins with one stop
Seattle-Tacoma International Airport (SEA)	London Heathrow Airport (LHR)	SEA–DEN–LHR	Around 12 hrs 56 mins with one stop
Seattle-Tacoma International Airport (SEA)	London Heathrow Airport (LHR)	SEA–CDG–LHR	Around 13 hrs with one stop
Seattle-Tacoma International Airport (SEA)	London Heathrow Airport (LHR)	SEA–DTW–LHR	Around 13 hrs 17 mins with one stop

These journey times are useful estimates rather than fixed durations. The actual schedule can change according to the airline, operating day, connection length, air traffic and weather conditions.

Which Airlines Provide Nonstop Seattle to London Flights?

British Airways

Delta Air Lines

Virgin Atlantic

What Is the Time Difference Between Seattle and London?

London is normally eight hours ahead of Seattle, but there are short periods each year when the difference becomes seven hours because the United States and United Kingdom change their clocks on different dates.

Seattle uses Pacific Standard Time (UTC−8) during winter and Pacific Daylight Time (UTC−7) during its daylight-saving period. London follows Greenwich Mean Time (UTC±0) in winter and British Summer Time (UTC+1) during the warmer months. During most of the year, these schedules maintain an eight-hour difference.

For example, when it is 10:00 AM in Seattle, it is usually 6:00 PM in London.

The time zone change also explains why most Seattle-to-London flights arrive on the following calendar day. A passenger leaving Seattle during the afternoon or evening may spend less than ten hours in the air but land in London the next morning or afternoon because arrival times are displayed using UK local time.

Explore More Flight Times & Routes

Planning beyond this route? Explore more flight times, distances, and travel durations using our tools below.

Start with our Flight Time Calculator to estimate journey times worldwide, or browse average travel times from your departure city using the Seattle Flight Times.