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.
Chilean Central Valley
The valley runs an un-interrupted leght of 360 km from Angostura de Pelequén in the north to Bío Bío River (37°40' S) in the south. It broadens from 12 km at Molina (35°05' S) in the north to 74 km in the south at Laja (37°15' S) the relief being gently undulating. Conglomerate of Andean provenance cover large swathes of the Central Valley being less common to the west near the Coast Range. Occasionally the valley contains isolated hills and mountains made up of basement rocks. At the latitudes of Temuco the Coast Range is subdued to such degree the Central Valley coalesces with the coastal plains.