Mountains can affect climate. Because mountains have a higher elevation than the surrounding area, temperatures in mountainous areas are cooler than other nearby areas. These areas also receive more precipitation than lower elevations. The fact that mountains receive and hold moisture is very important for life. In cooler climates, mountains store water as ice and snow until the summer months, when it becomes warmer. As the snow and ice melt, gravity moves the water into surrounding areas through rivers and streams. These rivers and streams are used by both plants and animals. Therefore, mountain climate affects both the biosphere and the hydrosphere.

As you will see on the next page, a mountain's climate can change significantly from its windward side (the side that faces incoming weather) to its leeward side (the side opposite from incoming weather). The windward side receives large amounts of precipitation, while the leeward side receives very little. This affects the types of vegetation and animals that can survive in ecosystems on either side of a mountain. In fact, many of Earth's deserts are found in a mountain's rain shadow. One example is Death Valley.


Source: http://www.teachersdomain.org/resource/nat08.earth.meteo.var.clouds/