(1) The ratio of the amount of water in the air at a give temperature to the maximum amount it could hold at that temperature; expressed as a percentage
- The ratio of the actual amount of water vapor (absolute humidity) present in the air to the saturation point at the same temperature. The point at the same temperature. The corresponding ratios of specific humidity or of mixing ratio give approximations of sufficient accuracy for many purposes in meteorology. The relative humidity is usually expressed in percent and can be computed from psychrometric data.