Does Hard Water Boil at a Higher Temperature?

How Minerals Affect Water Boiling Point

Hard water boils at a slightly higher temperature than ordinary water.
Hard water boils at a slightly higher temperature than ordinary water. Dave Rudkin / Getty Images
by Anne Marie Helmenstine, Ph.D.
Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels.
Updated July 08, 2019

Does hard water boil at a higher temperature than pure water or regular tap water? The answer is yes. The difference in temperature usually is a degree or two. Hard water contains dissolved minerals, which cause boiling point elevation. Adding salt to water produces a similar effect. The more dissolved minerals in the water, the greater the effect. However, it's not as significant as the effect of elevation on boiling point.