Flights Seattle → London
SEA → LHR
How long is the flight from Seattle to London?
The flight from Seattle (SEA) to London (LHR) takes 8h 38m on average. That is the median time recorded across 1 scheduled flight on this leg; the actual time varies by a few minutes with wind, routing and take-off queues.
Route overview
The flight route from Seattle to London boasts a perfect on-time performance record, with flights arriving an average of twenty minutes ahead of schedule. Over the course of six total flights, passengers travel in Boeing 777 and Boeing 747-400 aircraft to one of the world's busiest airports, which serves over eighty-three million passengers annually.
Your rights on this US flight (DOT)
US flights have no statutory cash compensation for delays. Under the US DOT rules, if your flight is cancelled or significantly changed and you decline rebooking, you're owed an automatic refund of the unused ticket. The tarmac-delay limit is 3 hours (domestic) / 4 hours (international). Amenities for controllable delays depend on each airline's contract of carriage.
US flight refund rules & checker →General information, not legal advice.
The Seattle (SEA) → London (LHR) route is operated by American Airlines, Air France, British Airways, Delta Air Lines, Iberia Airlines, KLM Royal Dutch Airlines. Across 20 flights monitored in recent months, 71% arrived on time (within 15 min of schedule), with an average delay of -45 minutes. The cancellation rate is 0.00%. FlightGuard's average computed risk is 9/100 (low), updated in real time from weather, ATC delays, strikes, NOTAMs, fuel and flight history. At London the average ATFM delay is 1.8 minutes (main cause: atfm). Departing from Seattle the average ATFM delay is 5.5 minutes.
Heading to London: what to expect in this direction
Flying from Seattle (SEA) to London (LHR) heads north-east for about 7,702 km, a flight time of roughly 8h 38m.
Departures from Seattle on this leg cluster in the midday window: about 100% of SEA-LHR flights take off then.
Air-traffic congestion: departing Seattle the average ATFM delay is 5.5 min (atfm); arriving into London it is 1.8 min (atfm).
Across 20 tracked SEA-LHR flights, 71% left on time with an average delay of -45 min and a 0.0% cancellation rate.
Route facts
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Airline punctuality on this route
| Airline | On-time | Average delay | Cancellations |
|---|---|---|---|
| Iberia Airlines (IB) | 87% | 20 min | 1.2% |
| Delta Air Lines (DL) | 85% | 1 min | 0.8% |
| Air France (AF) | 82% | 28 min | 0.0% |
| KLM Royal Dutch Airlines (KL) | 82% | 19 min | 5.9% |
| American Airlines (AA) | 79% | 6 min | 1.1% |
| British Airways (BA) | 66% | 31 min | 1.3% |
Airlines operating SEA-LHR
Airports
Frequently asked questions about SEA-LHR
The flight from Seattle (SEA) to London (LHR) takes 8h 38m on average. That is the median time recorded across 1 scheduled flight on this leg; the actual time varies by a few minutes with wind, routing and take-off queues.
On the Seattle (SEA) -> London (LHR) route, on-time performance is 71% with an average delay of -45 minutes, based on 20 tracked flights.
The cancellation rate on Seattle-London is 0.00% across 20 monitored flights.
The route is operated by 6 airlines: American Airlines, Air France, British Airways, Delta Air Lines, Iberia Airlines, KLM Royal Dutch Airlines.
Enter your flight number on FlightGuard for a real-time analysis based on 9 factors: weather at London, ATC delays, strikes, NOTAMs, fuel, airline punctuality and recent trends.
US flights have no statutory cash compensation for delays. Under US DOT rules, if the airline cancels or significantly changes your flight and you decline rebooking, you're owed an automatic refund of the unused ticket. The tarmac-delay limit is 3 hours (domestic) / 4 hours (international). Meals or hotels for controllable delays depend on each airline's contract of carriage.
