Wet Bulb Temperature

The temperature at which water, by evaporating into air, can bring the air to saturation at the same temperature.

Traditionally this was the temperature indicated by a thermometer whose bulb is wrapped in a wet sheath. The wet bulb temperature and the dry bulb temperature (i.e air temperature) would then be used to calculate relative humidity or dewpoint. Alternatively charts or tables can be used. Wet-bulb Temperature

See also: Thermometer, Wet Bulb Thermometer.

Further reading:
• Guide to Weather, Ross Reynolds, Philip′s