Altius recorded 305 priced readings of nonstop business-class round trips from Boston (BOS) to Zurich (ZRH) booked 90 days out, across 137 departure dates between 2026-05-20 and 2026-10-05. Observed fares ran from US$4,528 to US$10,822. The lowest fare Altius scored on this window was US$4,528 for a 2026-08-21 departure, seen on 2026-05-23 — RARE at the time, 37% below the US$7,187 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.