How Cold Is It At The Top Of Mount Everest

The summit of Mount Everest, the highest point on Earth, is a place of extreme conditions, and understanding the temperature there is crucial for climbers planning an ascent. It's not just about the height; many factors contribute to the bitter cold that reigns over the mountain's peak.

Factors Influencing Temperature on Mount Everest

Several factors combine to create the extreme cold at the summit of Mount Everest:

• Altitude: As altitude increases, air pressure decreases. This lower pressure causes air to expand. When air expands, it cools. This is known as adiabatic cooling. For every 1,000 meters (approximately 3,300 feet) of altitude gained, the temperature drops by roughly 6.5 degrees Celsius (11.7 degrees Fahrenheit). Given Everest's staggering height of 8,848.86 meters (29,031.7 feet), the baseline temperature is already significantly lower than at sea level.
• Latitude: Everest is located at approximately 28 degrees north latitude, which places it in a region that experiences significant seasonal temperature variations. During winter months, this latitude experiences colder temperatures, exacerbating the already frigid conditions caused by altitude.
• Solar Radiation: While the sun's rays are intense at high altitudes, the thin air is unable to retain much of the heat. This means that while direct sunlight can warm exposed surfaces, the ambient air temperature remains extremely cold. Furthermore, the mountain's snow-covered surface reflects a large portion of the solar radiation, reducing the amount of heat absorbed.
• Wind: The summit of Everest is constantly exposed to strong winds, which can significantly lower the effective temperature through wind chill. High winds strip away any thin layer of warm air that might be present around exposed skin, leading to rapid heat loss and increasing the risk of frostbite.
• Time of Year: The coldest months on Everest are typically December and January. During this period, the jet stream often dips south, bringing extremely cold air from the polar regions over the Himalayas. Climbing expeditions usually avoid these months due to the increased danger.
• Time of Day: Temperatures can fluctuate throughout the day. Direct sunlight can provide some warmth during the daytime, but as soon as the sun dips behind a ridge or sets, temperatures plummet rapidly.

Average Temperatures on the Summit

Given these factors, what temperatures can climbers expect at the top of Everest?

The average temperature at the summit of Mount Everest in January is around -36 degrees Celsius (-33 degrees Fahrenheit). However, this is just an average. Temperatures can drop much lower, especially when combined with wind chill.

During the climbing season, which typically runs from April to May, temperatures are slightly warmer, averaging around -20 degrees Celsius (-4 degrees Fahrenheit). While this is still extremely cold, it's a more manageable range for climbers equipped with proper gear.

It's important to remember that these are average temperatures. Climbers must be prepared for sudden and extreme temperature drops due to weather changes. A sunny day can quickly turn into a blizzard with whiteout conditions and plummeting temperatures.

The Role of Wind Chill

Wind chill is a critical factor in understanding the true impact of the cold on Mount Everest. Wind chill is the perceived decrease in air temperature felt by the body on exposed skin due to the flow of air. In simple terms, it's how cold it feels to your skin.

Even if the air temperature is -20 degrees Celsius, a strong wind can make it feel like -50 degrees Celsius or lower. This dramatically increases the risk of frostbite and hypothermia.

Climbers use specialized wind chill charts and weather forecasts to estimate the effective temperature and adjust their gear and strategy accordingly.

Historical Temperature Extremes

There are no permanently installed weather stations on the summit of Mount Everest, so precise historical temperature records are limited. However, based on meteorological data and climber reports, the coldest recorded temperature on Everest is estimated to be around -73 degrees Celsius (-99 degrees Fahrenheit). This extreme cold would have been accompanied by high winds, making the wind chill factor even more severe.

These extreme temperatures highlight the incredibly harsh conditions that climbers face and the importance of meticulous preparation and appropriate gear.

Impact on Climbers

The extreme cold on Mount Everest has profound effects on climbers:

• Frostbite: This is a common and serious risk. Frostbite occurs when body tissue freezes, typically affecting extremities like fingers, toes, nose, and ears. In severe cases, frostbite can lead to amputation.
• Hypothermia: This occurs when the body loses heat faster than it can produce it, leading to a dangerous drop in core body temperature. Hypothermia can impair judgment, coordination, and eventually lead to unconsciousness and death.
• Reduced Cognitive Function: Extreme cold can impair cognitive function, making it difficult for climbers to make sound decisions. This is particularly dangerous in the "death zone" above 8,000 meters, where climbers are already oxygen-deprived.
• Increased Risk of Accidents: Cold and fatigue can increase the risk of accidents, such as falls and slips. The terrain on Everest is already treacherous, and impaired judgment makes it even more dangerous.
• Equipment Failure: Extreme cold can cause equipment to malfunction. Batteries drain quickly, ropes can become brittle, and oxygen regulators can freeze up.

Protective Measures

To mitigate the risks associated with extreme cold, climbers take extensive precautions:

• Specialized Clothing: Climbers wear multiple layers of high-tech clothing designed to trap heat and wick away moisture. This includes thermal underwear, fleece jackets, insulated parkas, and windproof outer layers.
• Insulated Boots and Gloves: Keeping extremities warm is crucial. Climbers use heavily insulated boots and gloves, often with battery-powered heating elements.
• Oxygen Systems: While not directly related to warmth, supplemental oxygen helps climbers maintain body temperature by reducing the strain on their cardiovascular system. It also helps prevent cognitive impairment.
• Acclimatization: Spending time at progressively higher altitudes allows the body to adjust to the lower oxygen levels and colder temperatures. This process, called acclimatization, is essential for preventing altitude sickness and improving performance.
• Careful Planning and Weather Monitoring: Climbers meticulously plan their ascents, taking into account weather forecasts and potential risks. They monitor weather conditions closely and are prepared to turn back if necessary.
• Buddy System: Climbing with a partner allows climbers to monitor each other for signs of frostbite, hypothermia, and other cold-related problems.

The Science Behind the Cold

To fully grasp the cold on Mount Everest, it's helpful to understand some of the scientific principles at play.

• The Lapse Rate: The rate at which temperature decreases with altitude is known as the lapse rate. The standard lapse rate is approximately 6.5 degrees Celsius per 1,000 meters. However, the actual lapse rate can vary depending on atmospheric conditions.
• Heat Transfer: The human body loses heat through several mechanisms:
  • Conduction: Heat transfer through direct contact with a colder object.
  • Convection: Heat transfer through the movement of fluids (air or water).
  • Radiation: Heat transfer through electromagnetic waves.
  • Evaporation: Heat loss through the evaporation of sweat.
• Thermoregulation: The human body has mechanisms to regulate its internal temperature. However, these mechanisms can be overwhelmed in extreme cold. Shivering, for example, is a reflex that generates heat by contracting muscles.
• The Physics of Ice and Snow: Snow and ice have high albedo, meaning they reflect a large portion of the sun's radiation. This reduces the amount of heat absorbed by the surface and contributes to the overall cold. Additionally, the sublimation of ice (transitioning directly from solid to gas) requires energy, which further cools the surrounding environment.

Is Global Warming Affecting Temperatures on Everest?

There's growing evidence that global warming is affecting temperatures on Mount Everest and other high-altitude regions. Glaciers are melting at an alarming rate, and permafrost is thawing, leading to increased instability and risks for climbers.

While it's difficult to isolate the effects of global warming on summit temperatures, studies suggest that the overall trend is towards warmer temperatures. This could potentially lead to changes in weather patterns, snow conditions, and the length of the climbing season.

However, it's important to note that even with global warming, the summit of Everest will remain an extremely cold and dangerous place. The altitude and other factors that contribute to the cold are unlikely to change significantly in the foreseeable future.

The Future of Everest Climbing

As technology advances, climbers will likely have access to better equipment and more accurate weather forecasts. This could potentially make climbing Everest slightly safer, but it will never eliminate the inherent risks.

The extreme cold, combined with the altitude, terrain, and unpredictable weather, will continue to challenge even the most experienced and well-prepared climbers. Mount Everest will likely remain a formidable and awe-inspiring peak for generations to come.

Conclusion

The summit of Mount Everest is one of the coldest places on Earth, with average temperatures ranging from -20 degrees Celsius during the climbing season to -36 degrees Celsius in winter. These temperatures, combined with strong winds, can create extreme wind chill factors, leading to a high risk of frostbite, hypothermia, and other cold-related problems. Climbers must take extensive precautions, including wearing specialized clothing, using oxygen systems, and carefully monitoring weather conditions. Understanding the science behind the cold and the factors that contribute to it is essential for planning a successful and safe ascent. While global warming may be affecting temperatures on Everest, the summit will likely remain an incredibly challenging and dangerous environment for the foreseeable future.