Potential evaporation
![This animation shows the projected increase in potential evaporation in North America through the year 2100, relative to 1980, based on the combined results of multiple climate models.](/Images/godic/202502/04/-Potential_Evaporation_in_North_America_Through_2100.ogg5157.jpg")
Potential evaporation or potential evapotranspiration (PET) is defined as the amount of evaporation that would occur if a sufficient water source were available. If the actual evapotranspiration is considered the net result of atmospheric demand for moisture from a surface and the ability of the surface to supply moisture, then PET is a measure of the demand side. Surface and air temperatures, insolation, and wind all affect this. A dryland is a place where annual potential evaporation exceeds annual precipitation.