What Is the Boiling Point of Water?

The simple answer to this question is that the boiling point of water is 100 °C or 212 °F at 1 atmosphere of pressure (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).

The boiling point of water also depends on the purity of the water. Water that contains impurities (such as salted water) boils at a higher temperature than pure water. This phenomenon is called boiling point elevation, which is one of the colligative properties of matter.

Learn More

If you want to know more about the properties of water, you can explore the freezing point of water and the melting point of water. You can also contrast the boiling point of water to the boiling point of milk.

Sources

• Goldberg, David E. (1988). 3,000 Solved Problems in Chemistry (1st ed.). McGraw-Hill. section 17.43, p. 321. ISBN 0-07-023684-4.
• West, J. B. (1999). "Barometric pressures on Mt. Everest: New data and physiological significance." Journal of Applied Physiology. 86 (3): 1062–6. doi:10.1152/jappl.1999.86.3.1062