Mount Everest, the world’s highest peak, reaches an astonishing 8,848.86 meters (29,031.7 feet) above sea level. This majestic mountain is celebrated for its immense height and its exceptionally harsh and unforgiving climate.
The Cold Reality of Everest’s Summit
Temperatures on Mount Everest’s summit remain well below freezing throughout the year. During the winter months, from December to February, average temperatures at the peak hover around -36°C (-32.8°F) to -37°C (-35°F). Temperatures can plunge further at night, sometimes reaching -60°C (-76°F).
Even in the relatively warmer summer months (June to August), the summit averages between -18°C (-0.4°F) and -20°C (-4°F). Temperatures never rise above freezing at the very top.
Temperatures fluctuate across seasons. Spring (April and May) sees summit temperatures between -20°C and -30°C (-4°F to -22°F). Autumn (October and November) experiences a rapid cooling, with temperatures dropping to -27°C to -30°C (-16.6°F to -22°F). In stark contrast to the summit, Everest Base Camp, located much lower at around 5,000 meters, experiences significantly milder conditions, with winter lows averaging around -15°C to -20°C (1.4°F to -4°F) and summer daytime temperatures reaching up to 22°C (72°F).
Factors Shaping Everest’s Climate
The extreme cold on Mount Everest is a direct consequence of its immense altitude, due to the atmospheric lapse rate. This phenomenon dictates that temperature decreases with increasing elevation, typically by about 6°C for every 1,000 meters ascended. The air at higher altitudes is thinner and less dense, meaning it cannot retain heat effectively, despite direct solar radiation.
Wind chill amplifies the sensation of cold. Hurricane-force winds, frequently exceeding 120 kilometers per hour (74 mph), are common on the summit, particularly during winter. These intense winds can drive the perceived temperature down to an astonishing -70°C (-90°F).
The jet stream, a narrow band of strong winds, directly impacts Everest’s climate, engulfing the peak for much of the year. This subtropical jet stream can generate sustained winds of approximately 120 kph, with gusts reaching up to 285 kph. Its northward shift in May temporarily reduces wind speeds, creating a brief window for climbing.
Atmospheric pressure at the summit is remarkably low, roughly one-third of that at sea level. This reduced pressure means there is significantly less oxygen available, which contributes to the harsh environment. Despite the thin air, high altitudes on Everest receive intense solar radiation due to less atmospheric scattering and absorption, but this energy is not retained by the sparse air.
Life at Extreme Temperatures
The cold on Mount Everest shapes its environment, leading to the prevalence of vast glaciers and extensive ice fields across the landscape. These icy formations are preserved by the consistently low temperatures, with some glaciers thinning primarily through sublimation—a process where ice directly turns into vapor—rather than melting. The extreme cold also means that liquid water is scarce, existing mostly in a frozen state, which limits biological activity dependent on it.
Despite these formidable conditions, certain forms of microbial life demonstrate remarkable resilience. Hardy microorganisms, often categorized as extremophiles, have been found on Everest and can survive in a dormant state for decades or even centuries. Fungi from the genus Naganishia, for instance, are known for their ability to withstand extreme cold and high levels of ultraviolet radiation. Even human-associated microbes, such as Staphylococcus and Streptococcus, have been detected, though they are generally unlikely to grow or reproduce in such an inhospitable environment.
For humans, exposure to Everest’s extreme temperatures poses serious physiological challenges. The severe cold, coupled with high winds and low humidity, elevates the risk of frostbite and hypothermia. Maintaining the body’s core temperature is a constant struggle in this environment. These conditions underscore the profound impact of temperature on life forms attempting to exist or traverse the world’s highest peak.