Western Alps: a dry window, but hot afternoons

High pressure has settled over the Western Alps. Chamonix and Zermatt both show three dry days ahead, with valley highs climbing from 22 to 28°C by Wednesday. That warmth is the catch. Afternoon heat softens the snow on the high routes and saps your legs on the way out. Start before dawn, top out by midday, and you keep firm ground under your boots and cool air in your lungs. A head torch earns its place in the pack.