Alpine climate is the average weather (climate) for a region above the tree line. This climate is also referred to as mountain climate or highland climate.
In the Köppen climate classification the alpine climate is part of "Group E," along with the polar climate, where no month has a mean temperature higher than 10 °C (50 °F). Certain highland climates can also fit under hemiboreal climate or Semi-arid climate groups of climate classification.
The climate becomes colder at high elevations—this characteristic is described by the lapse rate of air: air tends to get colder as it rises, since it expands. The dry adiabatic lapse rate is -10 °C per km of elevation or altitude. Therefore, moving up 100 meters on a mountain is roughly equivalent to moving 80 kilometers (45 miles or 0.75° of latitude) towards the pole. This relationship is only approximate, however, since local factors such as proximity to oceans can drastically modify the climate. The main form of precipitation is often snow, often accompanied by stronger winds.