In an aridic (and torric) soil moisture regime, potential evapotranspiration greatly exceeds precipitation during most of the year. In most years, little or no water percolates through the soil. This hydrologic regime has a distinctive influence on the development of such soils. During Quarternary time, most deserts have changed back and forth from cooler-moister, to warmer-more-arid climates, therefore, change in climatic conditions have to be considered when talking about Aridisols.