LHR to BOS flight delays
2,643 flights · March 2025 – August 2026 · UK Civil Aviation Authority and US Bureau of Transportation Statistics
79.38%
Arrived on time
Within 15 minutes of schedule
2.19%
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
Which airline you fly changes the odds here. American Airlines arrived on time 11.9 points more often than British Airways over the same period on the same route — same airports, same weather, same air traffic control. A gap that survives all of that is about how the two airlines are run.
The two directions do not behave alike. BOS to LHR arrives on time 5.2 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 London to Boston 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, American Airlines arrived on time most often on LHR to BOS. British Airways was late most often. Flights ran closest to schedule in October and worst in May.
Every airline on LHR to BOS
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 |
|---|---|---|---|---|---|
| British Airways | 1,410 | 73.83% | 2.7% | — | D |
| Virgin Atlantic | 752 | 85.56% | 1.46% | — | B |
| American Airlines | 480 | 85.77% | 1.88% | — | B |
| United Airlines | 1 | 100% | 0% | — | — |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
BOS to LHR Boston back to London 84.56% on time BOther routes from London
Common questions
Are flights from London to Boston usually delayed?
79.38% of flights on the LHR to BOS 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 London to Boston?
American Airlines, at 85.77% on time across 480 flights. The least punctual on the route was British Airways at 73.83%.
How often are LHR to BOS flights cancelled?
2.19% of scheduled flights did not operate — about 22 in every thousand. That is in the normal range.
What is the best month to fly London to Boston?
October, when 87.1% of flights arrived on time. The worst was June at 69.5%.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on LHR to BOS 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 →