The phenomenon whereby a descending air mass on the leeward side of a mountain becomes warmer and drier than the ascending air on the windward side is known as the

The föhn effect (also called the rain shadow effect) occurs because ascending air cools at the Saturated Adiabatic Lapse Rate (SALR) after condensation, losing moisture as precipitation on the windward side. The descending air on the leeward side warms at the Dry Adiabatic Lapse Rate (DALR), which is faster, making it warmer and drier than when it started its ascent. The urban heat island, continentality, and albedo effects are entirely different phenomena.