relative humidity

noun
1.
the amount of water vapor in the air, expressed as a percentage of the maximum amount that the air could hold at the given temperature; the ratio of the actual water vapor pressure to the saturation vapor pressure.
Abbreviation: RH, rh.
Also called humidity.
Compare absolute humidity, dew point, mixing ratio, specific humidity.
Origin
1810-20
Examples from the web for relative humidity
  • But previous research found only a weak correlation between the spike in flu rates and the drop in relative humidity.
British Dictionary definitions for relative humidity

relative humidity

noun
1.
the mass of water vapour present in the air expressed as a percentage of the mass that would be present in an equal volume of saturated air at the same temperature Compare absolute humidity
relative humidity in Medicine

relative humidity n.
The ratio of the amount of water vapor in the air at a specific temperature to the maximum amount that the air could hold at that temperature, expressed as a percentage.

relative humidity in Science
relative humidity  
The ratio of the actual amount of water vapor present in a volume of air at a given temperature to the maximum amount that the air could hold at that temperature, expressed as a percentage. Warm air can hold more water vapor than cool air, so a particular amount of water vapor will yield a lower relative humidity in warm air than it does in cool air. Compare absolute humidity.
Encyclopedia Article for relative humidity

ratio of the actual vapour pressure of water in the air to that in air saturated with water vapour; it is often expressed as a percentage. See humidity.

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