LHR to SFO flight delays
London (LHR) San Francisco, CA (SFO)
1,245 flights · January 2025 – August 2026 · UK Civil Aviation Authority and US Bureau of Transportation Statistics
76.45%
Arrived on time
Within 15 minutes of schedule
1.77%
Cancelled
Share of scheduled flights
—
When late, late by
Average across delayed arrivals
13 min
Delay per flight
Averaged over every flight flown
What the record says about this route
Which airline you fly changes the odds here. United Airlines arrived on time 12.9 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 London to San Francisco route sits close to the middle of the record — neither notably punctual nor notably late.
Which airline should you fly on this route?
Over January 2025 – August 2026, United Airlines arrived on time most often on LHR to SFO. British Airways was late most often. Flights ran closest to schedule in February and worst in January.
Every airline on LHR to SFO
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 | 546 | 81.77% | 2.56% | — | C |
| British Airways | 403 | 68.84% | 1.24% | — | D |
| Virgin Atlantic | 296 | 77.13% | 1.01% | — | C |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
SFO to LHR San Francisco back to London 77.34% on time COther routes from London
Common questions
Are flights from London to San Francisco usually delayed?
76.45% of flights on the LHR to SFO 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 San Francisco?
United Airlines, at 81.77% on time across 546 flights. The least punctual on the route was British Airways at 68.84%.
How often are LHR to SFO flights cancelled?
1.77% of scheduled flights did not operate — about 18 in every thousand. That is in the normal range.
What is the best month to fly London to San Francisco?
February, when 83.3% of flights arrived on time. The worst was June at 67.5%.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on LHR to SFO 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 →