Chile
The diverse climate of Chile ranges from the world's driest desert in the north—the Atacama Desert—through a Mediterranean climate in the center, humid subtropical in Easter Island, to an oceanic climate, including alpine tundra and glaciers in the east and south. According to the Köppen system, Chile within its borders hosts at least ten major climatic subtypes. There are four seasons in most of the country: summer (December to February), autumn (March to May), winter (June to August), and spring (September to November).
The flora and fauna of Chile are characterized by a high degree of endemism, due to its particular geography. In continental Chile, the Atacama Desert in the north and the Andes mountains to the east are barriers that have led to the isolation of flora and fauna. Add to that the enormous length of Chile (over ) and this results in a wide range of climates and environments that can be divided into three general zones: the desert provinces of the north, central Chile, and the humid regions of the south.
Transverse Valleys
The Transverse Valleys (Spanish: "Valles transversales") are a group of transverse valleys in the semi-arid northern Chile. They run from east to west (traversing Chile), being among the most prominent geographical features in the regions they cross. They are located in the Chilean regions of Valparaíso, Coquimbo, and Atacama. They share some characteristics, such as reaching the Pacific Ocean without passing through an Intermediate Depression, being rather deep and dissecting the landscape, concentrating most agriculture and population in the areas through which they pass, and being intensively cultivated. They are one of the defining elements the Chilean natural region of Norte Chico. The area of the Transverse Valleys spans roughly a length of 600 km from north to south.