The Camino Vasco del Interior crosses from the Basque Country’s showery Atlantic slopes to drier, more open country toward Burgos, producing changing weather and day–night contrasts. April, September, and October align with the shoulder-season windows described for this route, balancing changeable Basque weather with the drier stretches across Álava and into Burgos. Expect more rain and cloud near the coast, warmer and sometimes hotter afternoons inland, and periodic swings between sunny spells, showers, and occasional cold snaps through winter.