Zermatt: an 8-degree start, a 22-degree afternoon

Zermatt sat at 8.9°C at half six this morning and climbs to 22 by the afternoon. Chamonix is milder at the start, 13°C, topping out near 21. Neither valley sees rain for three days. That swing is the whole planning problem: dress for the early start and you overheat by eleven. Pack light. A merino base plus a wind shell covers both ends, and Tuesday's drop to 16°C in Zermatt is when the shell earns its place.