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, indicating how much moisture is in the air at a given time. It is typically expressed as a percentage, which shows the ratio of the current amount of water vapor compared to the maximum amount the air can hold at a specific temperature.

Precipitation refers to water that falls from the atmosphere to the ground in forms such as rain, snow, sleet, or hail and is not a measure of moisture in the atmosphere itself. Condensation is the process by which water vapor cools and changes into liquid water, forming clouds or dew, rather than being a direct measurement of vapor present in the air. Evaporation is the process of water turning from liquid to vapor, which is a mechanism that contributes to humidity but does not define the vapor itself in the air.