The Current Humidity map shows relative humidity, contoured every 10 percent, for the most recent hour. Relative humidity is defined as the amount of water vapor
in a sample of air compared to the maximum amount of water vapor
the air can hold at any specific temperature
in a form of 0 to 100%. Humidity may also be expressed as absolute humidity and specific humidity.
Relative humidity is an important metric used in forecasting weather
. Humidity indicates the likelihood of precipitation
, or fog
. High humidity makes people feel hotter outside in the summer
because it reduces the effectiveness of sweating to cool the body by preventing the evaporation of perspiration from the skin. This effect is calculated in a heat index
table. Warm water vapor
has more thermal energy than cool water vapor
and therefore more of it evaporates into warm air than into cold air.