A rain shadow is an area of dry land that lies on the leeward (or downwind) side of a mountain. Winds carry air masses up and over the mountain range and as the air is driven upward over the mountain, falling temperatures cause the air to lose much of its moisture as precipitation. Upon reaching the leeward side of the mountain, the dry air descends and picks up any available moisture from the landscape below. The resulting profile of precipitation across the mountain is such that rainfall and moist air prevails on the windward side of a mountain range while arid, moisture-poor air prevails on the leeward side of the mountain range.
The following locations are examples of dry, rain shadow regions and the mountain ranges that shield them:
- The Gobi Desert lies in the rain shadow of the Himmalayas.
- The Atacama Desert lies in the rain shadow of the Andes.
- The Patagonia region lies in the rain shadow of the Andes.
- Death Valley lies in the rain shadow of the Pacific Coast Ranges of California and the Sierra Nevada Mountains.
- The city of Spokane in the state of Washington lies in the rain shadow of the Cascade Mountain Range (Spokane receives little rainfall). Seattle, Washington lies on the windward side of the Cascades (it receives generous amounts of rainfall).