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.
Relative humidity is expressed as a measure of the amount of water vapor the air contains as a percentage of the total amount it could contain at a specific temperature. If you think of air as a paper towel for a moment, it can only hold a specific amount of water at a specific temperature.