Altius recorded 304 priced readings of nonstop business-class round trips from Washington (IAD) to Madrid (MAD) booked 90 days out, across 138 departure dates between 2026-05-20 and 2026-10-04. Observed fares ran from US$3,966 to US$11,443. The lowest fare Altius scored on this window was US$3,966 for a 2026-11-09 departure, seen on 2026-08-11 — IMPRESSIVE at the time, 23.1% below the US$5,157 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.