Traversing from Lausanne to Roma, the Via Francigena spans Alpine stages, the Po Plain, and the drier hills of Tuscany and Lazio, producing marked seasonal contrasts. April and September present broadly mild, walkable conditions across most sections, sidestepping deep winter in the north and the fiercest summer heat farther south. Weather transitions from lingering snow and rain in the Alps to warmer, often sunnier stretches toward central Italy, with humidity and occasional thunderstorms punctuating the plains and late-summer afternoons.