1. Humidity
The absolute humidity is the mass of the water vapor in a given volume of air or gas.
It’s unit of measurement is grams per cubic meter

2. Relative Humidity
Relative humidity is the ratio of the amount of water vapor in a volume of air compared to the amount needed for saturation at the same temperature
Saturation: a condition in which the amounts of precipitation and condensation are equal
Varies with temperature
Expressed as a percentage
Relative humidity=(actual amount of water/total amount the air can hold) X 100

3. Dew Point
As the temperature rises, the amount of water vapor the air holds also rises.
If the temperature cools, the atmosphere cannot hold as much water. When this happens, the water vapor leaves the air in the form of liquid water, this is called dew.
Dew point- when the water vapor turns to liquids
Varies each day and from place to place
Depends on the temperature and amount of water in the air

4. Human Perception Dew Human Perception Over 80°F
Severely high. Even deadly for asthma related
75-80°F
Extremely uncomfortable
70-74°F
Very humid, quite uncomfortable
65-69°F
Somewhat uncomfortable for most people at upper edge
60-64°F
OK for most, but all perceive the humidity as being high
55-59°F
Comfortable
50-54°F
Very comfortable
Under 50°F
A bit dry for some