Freezing rain is the name given to rain that falls when surface temperatures are below freezing. Unlike a mixture of rain and snow, ice pellets (both of which are sometimes called "sleet"), or hail, freezing rain is made entirely of liquid droplets. The raindrops become supercooled while passing through a sub-freezing layer of air hundreds of meters above the ground, and then freeze upon impact with any surface they encounter. The resulting ice, called glaze, can accumulate to a thickness of several centimeters. The METAR code for freezing rain is FZRA.