Alps: eight degrees colder by Friday

Zermatt sits at 20.3 °C today. By Friday the high is 12.2 °C, with nights down to 6.7 °C at 1,600 metres. That is an eight-degree slide in three days, and the freezing level drops with it. Chamonix takes 5 mm of rain first. Pack the fleece now. Anyone walking up mid-week wants a midlayer they would have left at home last weekend.