Altius recorded 313 priced readings of nonstop business-class round trips from Boston (BOS) to London (LHR) booked 60 days out, across 139 departure dates between 2026-05-20 and 2026-10-05. Observed fares ran from US$3,666 to US$6,446. The lowest fare Altius scored on this window was US$3,673 for a 2026-11-18 departure, seen on 2026-09-19 — DECENT at the time, 14.6% below the US$4,301 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.