The 'snow line' is the point above which, or poleward of which, snow and ice cover the ground throughout the year.
The interplay of
altitude and
latitude affect the precise placement of the snow line at a particular location. At or near the
equator, it is typically situated at approximately 4,500 meters (or about 15,000 feet) above
sea level. As one moves towards the
Tropic of Cancer and
Tropic of Capricorn, the parameter at first increases: in the
Himalayas the permanent snow line can be as high as 5,700 metres (18,700 feet). Beyond the Tropics the snow line becomes progressively lower as the latitude increases, falling all the way to sea level itself near the poles.
In addition, the relative location of a mountain to the nearest coastline can be a factor in how high the snow line would be; a peak near a coast — especially the west coast — of a continent might have a lower snow line than one of the same height and at the same latitude situated in a landmass interior, because the average summer
temperature of the surrounding lowlands would be warmer in the latter spot than in the former, thus making a higher altitude necessary to keep the snow from melting in the summer.
See also
★
Tree line