The temperature at which air becomes saturated with water, that is, when the air is at 100 percent
relative humidity. Below this temperature, moisture will condense and produce dew or fog. As air
is cooled, the amount of water vapor it can hold decreases. Expressed another way, the point
where the actual water vapor pressure becomes equal to the saturation water vapor pressure; any
further cooling beyond this point normally results in the condensation of moisture.