|Atmospheric pressure comparison||Pressure|
|Olympus Mons summit||0.03||0.0044|
|Hellas Planitia bottom||1.16||0.168|
|Mount Everest summit||33.7||4.89|
|Earth sea level||101.3||14.69|
|Dead Sea level||106.7||15.48|
|Surface of Venus||9,200||1,330|
In 2008, a new weather station at about 8000 m altitude (26,246 feet) went online. The station’s first data in May 2008 were air temperature −17 °C (1 °F), relative humidity 41.3%, atmospheric pressure 382.1 hPa (38.21 kPa), wind direction 262.8°, wind speed 12.8 m/s (28.6 mph, 46.1 km/h), global solar radiation 711.9 watts/m2, solar UVA radiation 30.4 W/m2. The project was orchestrated by Stations at High Altitude for Research on the Environment (SHARE), who also placed the Mount Everest webcam in 2011. The weather station is located on the South Col and is solar powered.
One of the issues facing climbers is the frequent presence of high-speed winds. The peak of Mount Everest extends into the upper troposphere and penetrates the stratosphere, which can expose it to the fast and freezing wind of the jet stream. In February 2004 a wind speed of 280 km/h (175 mph) was recorded at the summit and winds over 160 km/h (100 mph) are common. These winds can blow climbers off Everest. Climbers typically aim for the 7 to 10 day windows in the spring and fall when the Asian monsoon season is either starting up or ending and the winds are lighter. The air pressure at the summit is about one-third what it is at sea level, and by Bernoulli’s principle, the winds can lower the pressure further, causing an additional 14% reduction in oxygen to climbers. The reduction in oxygen availability comes from the reduced overall pressure, not a reduction in the ratio of oxygen to other gases.
In the summer, the Indian monsoon brings warm wet air from the Indian ocean to Everest’s south side. During the winter the West/South-West flowing jet stream shifts south and blows on the peak.
Source Courtesy: WIKIPEDIA