Highest altitude weather station on land

The highest-elevation terrestrial weather station is located at an altitude of 8,810 metres (28,904 feet) above mean sea level at Bishop Rock on the Nepalese side of Mount Everest (aka Sagarmāthā or Chomolungma), the world’s highest mountain at 8,849 m (29,031 ft). It was installed by an international team of scientists and Sherpa, led by Tenzing Gyalzen Sherpa, on 9 May 2022. The project was part of National Geographic and Rolex's "Return to Everest" Expedition organized by Appalachian State University (USA) in collaboration with King's College London (UK), the Department of Hydrology and Meteorology (Government of Nepal), Department of National Parks and Wildlife Conservation (Government of Nepal) and Tribhuvan University (Nepal). A paper detailing the project was published in the Bulletin of the American Meteorological Society on 1 December 2022.

The "Return to Everest" Expedition was a follow-up to the 2019 National Geographic and Rolex Perpetual Planet Everest Expedition during which a network of five automatic weather stations (AWSs) were installed on Everest. The highest of these, named “Balcony” and installed on 23 May 2019, was situated at 8,430 m (27,657 ft); it was the first ever terrestrial weather station to have been placed above 8,000 m (26,247 ft). However, high winds during its first winter saw the destruction of the station (Balcony stopped transmitting on 20 January 2020) so it was decided to return and replace the AWS at an even greater height on Bishop Rock (380 m/1,247 ft higher than Balcony). As part of the expedition, repairs were also made to the second-highest station in the array (South Col) at 7,945 m (26,066 ft).

There were some modifications to the meteorological equipment to try and better withstand the extreme weather conditions including double the number of bolts affixing the station to the bedrock and more robust wind sensors.

One of the key scientific reasons to go to all the effort of installing weather stations at such vertiginous heights is to study the little-understood Sub-tropical Jet Stream. These stations will also be able to collect much-needed data on high-elevation climate variables in the region, which impact on glacial activity and meltwater cycles, as well as providing observations to inform more accurate weather forecasts, which could dramatically improve safety and preparedness for climbers of the world's highest peak.

Photo credit: NGSPPEVR / Arbindra Khadka