—Madison Clark, Grand Rapids, Michigan In addition to temperature, relative humidity is a major factor in whether you can see your breath. If the air is cold (under 45 degrees Fahrenheit or so) and humid, it can’t hold much more water, so the water vapor in your breath condenses, and you can see it. (It’s similar to forming your own personal cloud!) But if the air is cold and dry, the moisture in your breath is quickly absorbed instead.
