Altius recorded 311 priced readings of nonstop business-class round trips from Boston (BOS) to Paris (CDG) booked 30 days out, across 137 departure dates between 2026-05-20 and 2026-10-04. Observed fares ran from US$3,057 to US$9,158. The lowest fare Altius scored on this window was US$3,057 for a 2026-07-26 departure, seen on 2026-06-26 — STRONG at the time, 16.4% below the US$3,657 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.