How high is the snow line in mountain ranges, and why does it change?

The snow line, or snowline, marks the elevation above which snow can survive through the warm season. It is not fixed: it changes with latitude, local climate, wind, slope direction, and the amount of sunlight a slope receives. Near the equator, the snow line can sit around 5,000 meters or higher, while in polar regions it can reach sea level. During colder ice ages, the snow line was much lower than it is today, which allowed glaciers to grow in more mountain regions. Because it responds quickly to temperature and precipitation, the snow line is an important climate indicator.