Altius recorded 246 priced readings of nonstop business-class round trips from London (LHR) to Philadelphia (PHL) booked 30 days out, across 120 departure dates between 2026-06-06 and 2026-10-05. Observed fares ran from US$5,644 to US$12,108. The lowest fare Altius scored on this window was US$5,644 for a 2026-08-27 departure, seen on 2026-07-28 — STRONG at the time, 20.4% below the US$7,090 this route was typically running that day.
A fare can move between our two readings of the same day, most often on the days furthest below typical. Where a day's two readings differ enough to matter, the chart marks that day and both readings can be read separately.