Zermatt read 9.5°C at 06:30 and climbs to 21.7°C this afternoon. Chamonix runs warmer: 13.7°C now, 21°C later. Neither sees a drop of rain before Monday. A dry spell this late is rare. Start cold, finish warm — a merino base under a light windproof covers the twelve-degree swing without a midlayer you end up carrying.
Merino base layers ↗