The windward side of a mountain is the side that faces the prevailing wind often experiencing higher rainfall than the leeward side of a mountain. This is because as air rises up the windward side of the mountain it cools adiabaticlly, causing the water vapour in the air to condense and fall as rain or snow. As the air descends on the leeward side of the mountain, it warms adiabaticlly, causing the water vapour in the air to evaporate and decreasing the likelihood of precipitation.
