Dew point indicates the amount of moisture in the air. The higher the dew points, the higher the moisture content of the air at a given temperature. The temperature in which water vapor would be at 20 degrees Celsius or 68 degrees Fahrenheit. The Relative humidity is defined as the ratio of the partial pressure of water vapor to the saturated vapor pressure at a given temperature
Relative Humidity = partial pressure of H₂0/saturated vapor pressure of H₂0 Multiply by 100%
Example at 20⁰C = 17.5 torr
That would mean 120% Humidity