weather term
Relative Humidity
The amount of moisture in the air expressed as a percentage of the maximum the air could hold at that temperature.
Because warm air can hold more moisture than cold air, the same relative humidity reading means something different depending on the temperature: 60% humidity on a cold winter day carries far less actual water vapour than 60% humidity on a hot summer afternoon. This is why dew point, an absolute rather than relative measure, is often a better guide to how muggy a day will actually feel.
Read the full article: What Does "Feels Like" Temperature Actually Mean?.