Humidity (absolute or actual humidity) : is the amount of moisture in air measured in grams of water per kilogram of air (g/kg) Saturated air: is air containing the maximum amount of moisture possible the saturated humidity depends on temperature (warmer air can “hold” more water vapour Dew Point temperature: the temperature that dew (condensation) will form when air is cooled humid air has a high dew point, dry air has a low point Relative Humidity: a measure of humidity in comparison to the maximum possible at 100% R.H., the air is completely saturated and the dew point is the SAME as the actual air temperature (rainy, foggy days and nights when dew or frost forms) in summer, high humidity makes the air feel “muggy or sticky” because water evaporates very slowly from our warm skin and sweating doesn’t cool us down in winter, high humidity feels cool and damp because the moist air absorbs heat from our skin RH = actual (dew point) humidity X 100% Maximum (actual temperature) humidity