Known to the Nepalese as Sagarmatha, which means “Goddess of the Sky,” Mount Everest holds a fascination among adventurers as the ultimate mountain-climbing achievement. Situated in the Himalayan range along the border between Nepal and Tibet, Everest’s superlative height among the giants of the Himalayas adds to both the allure and the challenge of climbing it. At an elevation of 29,029 feet (8,848 meters) above sea level, its summit straddles the upper-limits of the
troposphere, where the low density of the air imposes a formidable physical challenge for climbers, even with the aid of oxygen. Furthermore, Everest’s location makes it susceptible to the effects of the Asian monsoon, whose seasonal shift in wind direction brings blinding blizzard conditions and hurricane-force winds during the summer months. Because of this, most ascents are attempted during a very short window of time—typically during the month of May—after the winter season and before the onset of the monsoon.
After 3 decades of attempts on the mountain, New Zealand mountaineer Edmund Hillary and Nepalese Sherpa Tenzing Norgay became the first known climbers to successfully scale Everest on May 29, 1953. But while Hillary and Norgay often receive the credit, they were actually part of a much larger team led by British Colonel John Hunt.
Of all the factors that can make or break an attempt to climb Everest, the weather is perhaps the most critical. Hunt described the challenges in his 1954 book,
The Conquest of Everest: “So climbing Everest takes a long time...And in the final stages particularly, the saving of time is vital, not only because of physical deterioration but also because of another factor, the most important of all—weather.”
Hunt knew that regular weather reports would be essential to the team’s efforts and had arranged to have specialized forecasts supplied by the Indian Meteorological Service broadcasted daily by the All-India Radio and BBC Overseas networks.
The broadcasts began on May 1, 1953, more than 2 weeks after the team had established Base Camp at an elevation of 17,900 feet. The forecasts, as Hunt described, “foretold daily ‘snow showers’ with accuracy but monotonous regularity, useful to ourselves but giving little idea to other listeners to the trials and handicaps these ‘showers’ were proving to be to the toiling carries in the Icefall and the Cwm.” The Khumbu Icefall and the Western Cwm (pronounced “koom,” a Welsh word meaning valley) are two critical areas the climbers had to traverse on their way to the summit.
By May 10, members of the team who worked to clear a passage through the Icefall and Cwm encountered what Hunt described as “a depressing period,” due to the unrelenting daily snow showers: “On May 10th and 11th it snowed heavily from about midday until after dark, leaving a mantle of snow over a foot deep to be plowed through in the intense heat which filled the Cwm each morning, unrelieved by the faintest breeze. On the second of these days, Ed Hillary’s party took no less than 4 and a half hours between Camps III and IV, a journey which in fair conditions would be covered by a laden man in under 3 hours.”
As their journey progressed, the team was buoyed by a change in the weather. The relentless snow showers had ended, giving way to clear afternoons and the ability to push forward with greater speed and ease than before.
As Hunt and other team members waited at camp in the days before the final assault to the summit, they listened with more than a casual interest to the weather reports on the radio to learn what conditions awaited them. Tuning their shortwave radios one evening they heard the following:
This is the Overseas Service of the British Broadcasting Corporation. Here is the weather forecast for the Everest Expedition, valid for twenty-four hours commencing 12.00 hours G.M.T. or 17.30 hours Indian Standard Time...There will be mainly overcast skies with occasional thunderstorms, accompanied by moderate to heavy snow showers...Winds in free air at 29,000 feet above sea level will be mainly westerly at 35-40 miles, and the temperature in free air at the same altitude will be -16 to -12°F.
The team composed of Edmund Hillary and Tenzing Norgay was actually 1 of 2 pairs of climbers Hunt chose to attempt a final assault on the summit. The first pair, Charles Evans and Tom Bourdillon, came within 300 feet of the summit on May 26 before they had to turn back due to problems with their oxygen equipment. In his own account of the final assault in Hunt’s book, Hillary describes how he awoke “feeling very cold and miserable” in the early morning hours of May 27. “The relentless wind was blowing in all its fury and the constant loud drumming on the tent made deep sleep impossible,” he wrote. “Reluctantly removing my hand from my sleeping bag, I looked at my watch.
It was 4 a.m. In the flickering light of a match, the thermometer lying against the tent wall read -25° Centigrade.” Strong winds kept Hillary and Norgay from continuing until the following day, when they were able to climb to a height of about 27,900 before camping for the night. At 6:30 on the morning of May 29, they set out for the final assault on the summit. “The weather for Everest seemed practically perfect,” Hillary recalled of their final hours toward reaching their goal. “Insulated as we were in all our down clothing and windproofs, we suffered no discomfort from cold or wind.” At 11:30 a.m. local time, Hillary and Norgay took the final steps up a snowy ridge and stood, for the first time, on top of the world.
In more than half a century since their accomplishment, nearly 2,500 people have followed in Hillary and Norgay’s footsteps to reach the summit of Everest. However, considerable risks remain, not the least of which is the weather. Of the 210 people who have lost their lives attempting to climb Everest, 15 perished during the tragic 1996 climbing season, including 4 members of an expedition of which journalist Jon Krakauer was a member. Krakauer, who was on assignment for Outside magazine when “a rogue storm that blew in without warning” claimed the lives of his companions, went on to tell a more detailed account of the ordeal in his 1997 New York Times best-selling book, Into Thin Air. The passage that begins Krakauer’s book—taken from a 1938 volume by British mountaineer Eric Shipton titled, Upon That Mountain—seems as relevant to Hillary and Norgay’s pioneering achievement in 1953 as it does today:
The truth of course lies in the fact that, at altitudes of 25,000 feet and beyond, the effects of low atmospheric pressure upon the human body are so severe that really difficult mountaineering is impossible and the consequences even of a mild storm may be deadly, that nothing but the most perfect conditions of weather and snow offers the slightest chances of success, and that on the last lap of the climb no party is in a position to choose its day.
Weatherwise Contributing Editor SEAN POTTER is a Certified Consulting Meteorologist (CCM) and science writer who currently divides his time between the Washington, D.C., area and New York City.