Humidity Humidity Humidity is the amount of water vapour present in air. Water vapour, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. The amount of water vapour 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 vapour contained within a parcel of air can vary significantly. For example, a parcel of air near saturation may contain 28 grams of
SympaTex common polyurethane equivalent, it can also be referred to as a monolithic membrane. No water can get in from the outside, but water vapour molecules are transported through the membrane from the inside to the outside by way of an absorption and evaporation process. This moisture transfer through the membrane is what is referred to as "breatheability." A closed membrane like SympaTex differs from microporous membranes (such as Gore-Tex) which have microscopic pores that let air (and water vapour) pass through, yet have such low surface energy that the surface tension of any (liquid) water in contact remains too high