DEN to LHR flight delays
1,268 flights · March 2025 – August 2026 · US Bureau of Transportation Statistics and UK Civil Aviation Authority
78.35%
Arrived on time
Within 15 minutes of schedule
0.55%
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 February it ran 27.1 points more punctual than in June — 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.
This route does better than its own airport. Departures from DEN overall run 9.4 points less punctual than this particular one — so whatever congestion DEN has, this route is largely escaping it.
The 2 airlines here are separated by under 3 points — close enough to call a tie. Choose on price and departure time.
The Denver to London route sits close to the middle of the record — neither notably punctual nor notably late.
Which airline should you fly on this route?
Over March 2025 – August 2026, United Airlines arrived on time most often on DEN to LHR. British Airways was late most often. Flights ran closest to schedule in February and worst in May.
Every airline on DEN 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 |
|---|---|---|---|---|---|
| United Airlines | 790 | 79.36% | 0.63% | — | C |
| British Airways | 478 | 76.68% | 0.42% | — | C |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
LHR to DEN London back to Denver 79.71% on time BOther routes from Denver
Common questions
Are flights from Denver to London usually delayed?
78.35% of flights on the DEN to LHR route arrived within 15 minutes of schedule, so roughly 2 in every ten arrived late. That is about the same as the average route in this record.
Which airline is most on time from Denver to London?
United Airlines, at 79.36% on time across 790 flights. The least punctual on the route was British Airways at 76.68%.
How often are DEN to LHR flights cancelled?
0.55% of scheduled flights did not operate — about 6 in every thousand. That is in the normal range.
What is the best month to fly Denver to London?
February, when 92.7% of flights arrived on time. The worst was June at 65.6%.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on DEN to LHR during March 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 →