Temperature and Wind Chill on the Roof of the World
The weather at the Mount Everest summit is lethal. It is not just the cold; it is the wind. Understanding these extremes helps trekkers appreciate the gear needed for any Everest expedition.
Everest sits in the Jet Stream. Winds can exceed 100mph (160km/h). Summit windows open only when these winds die down. Climbing in high wind causes instant frostbite.
The air temperature might be -30°C, but with wind chill, it feels like -60°C. Exposed skin freezes in seconds. This is why Everest trekking gear, even for Base Camp, focuses heavily on windproofing.
Surprisingly, in the sun and out of the wind, it can feel warm due to intense solar radiation. Climbers often sweat while climbing the Western Cwm, only to freeze the moment the sun goes down.
There is no bad weather, only bad gear. But on Everest, even the best gear has limits.
