ICN to LHR flight delays
237 flights · January 2025 – August 2026 · UK Civil Aviation Authority
68.94%
Arrived on time
Within 15 minutes of schedule
0.84%
Cancelled
Share of scheduled flights
—
When late, late by
Average across delayed arrivals
12 min
Delay per flight
Averaged over every flight flown
What the record says about this route
The season swings this route hard. In June it ran 26.7 points more punctual than in April — 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.
The two directions do not behave alike. LHR to ICN arrives on time 14.5 points more 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 route has been getting better. The later months in the record run 10.6 points more punctual than the earlier ones, which usually means a schedule that was too tight has been given more room.
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.
Which airline should you fly on this route?
Over January 2025 – August 2026, Korean Air arrived on time most often on ICN to LHR. Flights ran closest to schedule in June and worst in April.
Every airline on ICN to LHR
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 | 211 | 67.62% | 0.47% | — | D |
| Virgin Atlantic | 26 | 80% | 3.85% | — | — |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
LHR to ICN London back to Seoul 83.4% on time BCommon questions
Are flights from Seoul to London usually delayed?
68.94% of flights on the ICN to LHR route arrived within 15 minutes of schedule, so roughly 3 in every ten arrived late. That is worse than the average route in this record.
Which airlines fly from Seoul to London?
Only Korean Air appears in the published record on this route, with 211 flights and 67.62% arriving on time.
How often are ICN to LHR 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 Seoul to London?
June, when 80% of flights arrived on time. The worst was April at 53.3%.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on ICN to LHR 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 →