Frozen rain is sometimes referred to as freezing rain. The term is used to describe super-cooled water droplets that freeze when they hit a cold surface.
Frozen rain is formed when precipitation falls through the atmosphere as a liquid but is immediately frozen as it hits the surface of a road, porch or other object. Generally, this occurs when rain or snow falls through warm air aloft in the atmosphere. Essentially, frozen rain is in a liquid form until it strikes a surface. The water droplets of frozen rain are super-cooled which makes them freeze on contact. Notably, frozen rain and sleet are two different types of precipitation.