What do we call the amount of water vapor present in the air?

The correct answer is humidity, which refers to the amount of water vapor present in the air at a given temperature and pressure. Humidity is a key concept in meteorology because it helps determine weather patterns, comfort levels, and the likelihood of precipitation. High humidity means there is a significant amount of water vapor in the air, which can lead to clouds, fog, and precipitation, while low humidity indicates drier conditions.

Precipitation refers specifically to any form of water, such as rain, snow, sleet, or hail, that falls from clouds to the Earth's surface. Dew point is the temperature at which air becomes saturated with moisture and water vapor condenses into liquid, representing a specific measure of humidity. Condensation involves the process by which water vapor in the air cools to form liquid water, but it is not a measure of the vapor itself. Thus, humidity is the most accurate term that describes the amount of water vapor in the atmosphere.