Climate is the statistics of weather, usually over a 30-year interval. It is measured by assessing the patterns of variation in temperature, humidity, atmospheric pressure, wind, precipitation, atmospheric particle count and other meteorological variables in a given region over long periods of time.
Once you have the saturation vapor pressure and the actual vapor pressure, relative humidity can be computed by dividing the actual vapor pressure by the saturation vapor pressure and then multiplying by 100 to convert the quantity to a percent. (7) Relative Humidity(RH) in percent =(E/Es)*100.
Humidity is simply the amount of water vapor in the air. The warmer the air, the more water vapor it can hold, which is why tropical areas tend to feel very humid. Relative humidity is the amount of water vapor the air can hold RELATIVE to how much water vapor that air can hold. It is temperature dependent. As air warms and cools, its relative humidity will fall and rise even though the amount of water vapor does not change.