Subnivean climate (From Latin for "under" () and "snow" () refers to the zone in and underneath snowpack. This is the environment of many hibernal animals, as it provides protection from predators and insulation. The subnivean climate is formed by three different types of snow metamorphosis: destructive metamorphosis, which begins when snow falls; constructive metamorphosis, the movement of water vapor to the surface of the snowpack; and melt metamorphosis, the melting/sublimation of snow to water vapor and its refreezing in the snowpack. These three types of metamorphosis transform individual snowflakes into ice crystals and create spaces under the snow where small animals can move.

Subnivean climate (From Latin for "under" () and "snow" () refers to the zone in and underneath snowpack. This is the environment of many hibernal animals, as it provides protection from predators and insulation. The subnivean climate is formed by three different types of snow metamorphosis: destructive metamorphosis, which begins when snow falls; constructive metamorphosis, the movement of water vapor to the surface of the snowpack; and melt metamorphosis, the melting/sublimation of snow to water vapor and its refreezing in the snowpack. These three types of metamorphosis transform individual snowflakes into ice crystals and create spaces under the snow where small animals can move.