B

LHR to ICN flight delays

London (LHR) Seoul (ICN)

237 flights · January 2025 – August 2026 · UK Civil Aviation Authority

83.4%

Arrived on time

Within 15 minutes of schedule

0.84%

Cancelled

Share of scheduled flights

When late, late by

Average across delayed arrivals

8 min

Delay per flight

Averaged over every flight flown

What the record says about this route

The two directions do not behave alike. ICN to LHR arrives on time 14.5 points less often than the outbound. Delay accumulates through the flying day, so whichever direction is scheduled later tends to carry the worse record — which is an argument for booking the morning departure if the choice exists.

The season swings this route hard. In June it ran 19.1 points more punctual than in May — a difference bigger than the one between the best and worst airlines on most routes. If the date is flexible, it is worth more than the carrier.

Only Korean Air flies this route in the published record, so there is no choice to weigh — the route's figures and the airline's are the same figures.

This is a thin route — 237 flights across the whole period. On a route this infrequent a cancellation is far more costly than the rate suggests, because the next departure may not be the same day.

Which airline should you fly on this route?

Over January 2025 – August 2026, Korean Air arrived on time most often on LHR to ICN. Flights ran closest to schedule in February and worst in May.

Every airline on LHR to ICN

Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.

Airline Flights On time Cancelled Avg delay Grade
Korean Air 212 84.83% 0.47% B
Virgin Atlantic 25 70.83% 4%

Month by month

Share of flights that arrived within 15 minutes of schedule, by month flown.

Jan 2025 peak 93 Jun 2026
On-time arrival rate, %

Common questions

Are flights from London to Seoul usually delayed?

83.4% of flights on the LHR to ICN route arrived within 15 minutes of schedule, so roughly 2 in every ten arrived late. That is better than the average route in this record.

Which airlines fly from London to Seoul?

Only Korean Air appears in the published record on this route, with 212 flights and 84.83% arriving on time.

How often are LHR to ICN flights cancelled?

0.84% of scheduled flights did not operate — about 8 in every thousand. That is in the normal range.

What is the best month to fly London to Seoul?

June, when 93.3% of flights arrived on time. The worst was May at 74.2%.

What these figures do and do not tell you

Everything on this page is counted from the flights that actually operated on LHR to ICN during January 2025 – August 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.

A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.

Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →