Temperatures at the Mount Everest summit average -33 degrees Fahrenheit during the winter and -2 degrees Fahrenheit during the summer. In the peak climbing season, temperatures at the summit average around -15 degrees Fahrenheit. At base camp, temperatures tend to hover around the freezing point, depending on the weather.
While the air temperature on Everest can be extremely cold, the powerful sun during the climbing season sometimes causes surprising temperature swings. Moving from shade into sunlight high on the mountain can leave a climber suddenly sweating and seeking to remove layers to prevent overheating. Those attempting the summit must bring a variety of tools, including plenty of water and sunscreen, to deal with the unique climate.