What is the term for water vapor present in the air?

The term for water vapor present in the air is humidity. Humidity specifically refers to the amount of water vapor in the atmosphere at any given time. It is an important concept because it affects weather conditions and can influence temperature and precipitation levels. High humidity levels can make the air feel warmer, while low humidity can make it feel cooler.

Precipitation refers to any form of water, such as rain, snow, sleet, or hail, that falls from the atmosphere to the surface of the Earth. Dew is the moisture that condenses on surfaces when temperatures cool at night, resulting from saturation of the air but not directly describing the overall moisture level in the air like humidity does. Evaporation is the process by which water changes from a liquid to a vapor, which contributes to the presence of humidity but is not a measure of the vapor itself in the air. This distinction makes humidity the correct answer to the question.