The Weather Window for the Mount Everest Summit
Every year, hundreds of climbers converge on Everest in May. Why this specific month? It all comes down to the Jet Stream and the monsoon. It's the 'Goldilocks' period for Mount Everest expeditions.
In winter, the Jet Stream blasts the summit with hurricane-force winds. In May, as the monsoon approaches from the south, it pushes the Jet Stream north, creating a calm period over the Everest summit.
May is warmer than October. This reduces the risk of frostbite. For Everest trekking, it means pleasant days and blooming rhododendrons lower down.
By early June, the monsoon snows arrive, making the mountain unstable and prone to avalanches. Climbers race to tag the summit before the window closes. This creates the 'traffic jams' seen on Everest expeditions.
We don't choose when to climb; the mountain chooses. May is when Everest opens its door.
