An onsen at the end of a ski day is not a bolt-on amenity in Japan — it is the structural rhythm of the trip. The country sits on so much volcanic groundwater that towns built around natural hot springs predate the lifts by centuries. The resorts in this guide are the ones where that pairing actually holds: the bath is genuine, the village is walkable from the snow, and you can spend an evening in slippers without driving anywhere.
Our onsen-tagged set is ranked by seasonal snowfall, because the resorts that combine deep snow with an onsen-village base tend to be the ones worth the trip — anywhere south of the snow belt, the onsen experience holds up but the skiing thins.
Below: how to read an onsen-resort listing, how the major regions differ in bath culture and snow, and the full onsen-tagged index.