Humidity is a term used to describe the amount of water vapor present in air. Water vapor, the gaseous state of water, is generally invisible to the human eye.[1] Humidity indicates the likelihood for precipitation, dew, or fog to be present. The amount of water vapor needed to achieve saturation increases as the temperature increases. As the temperature of a parcel of air decreases it will eventually reach the saturation point without adding or losing water mass. The amount of water vapor contained within in a parcel of air can vary significantly. For example, a parcel of air near saturation may contain 28 grams of water per cubic meter of air at 30 °C, but only 8 grams of water per cubic meter of air at 8 °C.
