LHR to PHL flight delays
London (LHR) Philadelphia, PA (PHL)
1,301 flights · March 2025 – August 2026 · UK Civil Aviation Authority and US Bureau of Transportation Statistics
71.55%
Arrived on time
Within 15 minutes of schedule
3%
Cancelled
Share of scheduled flights
—
When late, late by
Average across delayed arrivals
18 min
Delay per flight
Averaged over every flight flown
What the record says about this route
The season swings this route hard. In March it ran 35.4 points more punctual than in July — 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.
Cancellation, not delay, is the risk worth pricing here: 3% of scheduled flights never operated. A late flight still gets you there. A cancelled one leaves you rebooking, and on a route with few daily departures that can mean losing a day.
The two directions do not behave alike. PHL to LHR arrives on time 8.9 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.
Flights from London to Philadelphia run late more often than the average route, though not severely.
Which airline should you fly on this route?
Over March 2025 – August 2026, British Airways arrived on time most often on LHR to PHL. American Airlines was late most often. Flights ran closest to schedule in April and worst in July.
Every airline on LHR to PHL
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 |
|---|---|---|---|---|---|
| American Airlines | 813 | 71.19% | 3.94% | — | D |
| British Airways | 488 | 72.14% | 1.43% | — | D |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
PHL to LHR Philadelphia back to London 80.46% on time COther routes from London
Common questions
Are flights from London to Philadelphia usually delayed?
71.55% of flights on the LHR to PHL 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 airline is most on time from London to Philadelphia?
British Airways, at 72.14% on time across 488 flights. The least punctual on the route was American Airlines at 71.19%.
How often are LHR to PHL flights cancelled?
3% of scheduled flights did not operate — about 30 in every thousand. That is high enough that cancellation, not delay, is the risk worth planning around.
What is the best month to fly London to Philadelphia?
March, when 85.9% of flights arrived on time. The worst was July at 50.5%.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on LHR to PHL 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 →