At high altitudes, the atmospheric pressure is quite low as compared to that at sea level. So water boils at a lower temperature at high altitudes.
Does altitude affect cooking?
When atmospheric pressure is lower, such as at a higher altitude, it takes less energy to bring water to the boiling point. Less energy means less heat, which means water will boil at a lower temperature at a higher altitude. Cooking at high altitudes differs from cooking at sea level. The boiling point of any liquid depends on the atmospheric pressure bearing down on its surface: the higher the pressure, the more energy it takes for liquid molecules to escape the surface and become a gas, and so the higher the temperature at which the liquid boils.
