What is the boiling point of water at sea level?

The boiling point of water is 100 degrees Celcius or 212 degrees Fahrenheit at 1 atmosphere of pressure (at sea level). However, the value is not a constant. The boiling point of water depends on the atmospheric pressure, which changes according to elevation. Water boils at a lower temperature as you gain altitude (e.g., going higher on a mountain) and boils at a higher temperature if you increase atmospheric pressure (coming back down to sea level or going below it).

Source: ThoughtCo