This book examines the specific climatic characteristics of a major and complex orographic barrier on the Continent (representing about 32% of the most extended European mountain range - the Carpathian Chain), with focus on the regional climate patterns and vertical climatic zonation at above 1,000 m. It represents a comprehensive analysis of climatological data from instrumental records at 17 weather sites, covering a 47-year period of meteorological observations, which meet the World Meteorological Organization requirements (e.g. length, homogeneity). It outlines the specific features of the air temperature, precipitation, wind, snowfall and snowpack regimes and the climate records, in relation to the main climatogenic factors of mountain climates (e.g. latitude, continentality, altitude, mountain topography), as well as with the interactions between atmospheric forcing and the underlying mountain topography. Special emphasis is given to the climate change signals in the variability of four key climatic variables (air temperature, precipitation, wind and snow), as well as associated changes in climate extremes. The book provides a broad scientific base to understand the current climate patterns, as well as regional and local evidence of an ongoing and widespread warming and drying process of an important mountain range of the South-Eastern Europe, located at the transition from the wetter westerly and south-westerly climates to the easterly drier one. Valuable comparisons between the change signals in these mountains to those observed in other European mountain ranges are also presented. Results of the future climate change simulations and expected physical impacts by the end of the 21st century in the Romanian Carpathians are summarized in this work.