Climatic conditions. – From the climatic point of view, Chile can be divided, as we have mentioned, into three large sections, each of which corresponds to a specific type of climate. Morphological and astronomical reasons, the different distribution of winds and currents (especially the cold one in the south) explain the great differences that are found between zone and zone. For Chile geography, please check franciscogardening.com.
As regards the temperature, we must first of all observe how the Chilean coastal area has temperatures lower than those found at the same latitude on the Atlantic Ocean. Thus, while Pelotas (Río Grande do Sul) at a latitude of 32 ° has an average annual temperature of 17 °, 8, Coquimbo on the Chilean coast, at 30 °, has only 15 ° on average; Buenos Aires (35 ° lat. S.) 16 °, 6, Valparaiso (33 ° lat. S.) 14 °, 3; Patagones (about 41 °) 14 °, 7, Valdivia (40 °) 11 °, 6.
The average annual temperature of the Chilean coastal area gradually decreases as we proceed towards the south: from 19 °, 7 ° in Arica we go down to 14 °, 3 ° in Valparaiso; at 10 °, 6 of Puerto Montt, at 6 °, 3 of Punta Arenas. Noteworthy is the low temperature of the northern provinces which, although entering the astronomical domain of the tropic, are far from having a corresponding climate. The internal stations also show a very slow decrease of the average temperature: Copiapó, at 395 msm, and at 27 ° 22 ′ lat. S., has an average of 16 °, 4; Santiago at 530 m. and at 34 ° lat. S., 13th, 6; Talca at 105 m. and at 35 ° 26 ‘, 13 °, 6.
The temperatures of the coldest month oscillate between a maximum of 17.3 ° for Arica and a minimum of 1.9 ° for Punta Arenas (Magallanes) in Tierra del Fuego; those of the hottest month between 22 ° (Arica) and 10 ° (Punta Arenas).
The annual excursion is therefore very modest, but it is greater in the centers of the interior which, at greater height and less influenced by the sea, have warmer summers and colder winters. Suffice it to mention the example of Valparaiso and Santiago. The first, on the sea, has the coldest month with 11 °, 4; Santiago with 7 °, 5, but the hottest month for Valparaiso is 17 °, 3 while for the capital it is 19 °, 9. So for Valparaiso the excursion is 6 °, for Santiago it goes up to 12 °, 4; in Constitución, on the sea, there are 7 °, 5; in Talca, in the inner plain, a good 14 ° of annual excursion.
More violent contrasts occur for precipitation: it ranges from a minimum of 0 mm. to a maximum of 3000-4000 mm. I nod through a series of gradations.
The northern provinces are absolutely desert-like: 0.6 mm fall in Iquique, 17 mm in the interior at Copiapó. only! In these desolate areas, the rains fall at very long intervals, sometimes for a few years. The mists, locally called camachancas, in the region of the coastal Cordillera between Iquique and Antofagasta, give a little benefit, which allow a certain shrub vegetation.
Starting from the province of Coquimbo, the rains begin to be less scarce: in La Serena, 147 mm falls, rising to 515 in Valparaiso (in Santiago, in the interior, 364), to 576 in Constitución.
Central Chile therefore has a fair amount of rainfall which is increasing towards the south. Thus we enter the third section of Chile, the intensely humid and rainy one; in Concepción 1296 mm fall; 2698 in Valdivia; 2160 in Puerto Montt; 2092 in Ancud; Corral, at 39 ° 53 ‘of lat. S., with 12 years of observation, has 3101 mm. rain. The maximum would be in Bahía Felix, at 52 ° 58 ′ lat. S., with a good 5479 mm .; but the observation period is too short to have safe averages. In Patagonia, the rains decrease, although they always remain very abundant.
The number of rainy days going south first increases until it reaches a maximum of 207 at the Puerto Montt station; therefore, proceeding towards Patagonia, it decreases. As for distribution, mainly winter rains (Mediterranean type) prevail in central Chile, while towards the south every month there is rainfall, but preferably in the winter period. Thus, in Santiago the rains that fell from April to September represent 90% of the total; in Valdivia for the same period it drops to 71%; in Puerto Montt, 62%; in Punta Arenas, 61%; to Evangelistas (52 ° 24 ‘), 49%.
The nebulosity increases as you proceed south; while in Copiapó the number of clear days is 273, in Santiago it drops to 193, in Talca to 160, in Puerto Moutt to 48, in Punta Arenas to 46.
Hydrography. – The morphological and climatic conditions explain why Chile is poor in long-flowing rivers, why the flow of its waterways is extremely variable according to the latitude and the seasons, and why, given the strong differences in height due to the presence of the high Andean reliefs, most of the torrential waterways are not navigable at all.
In northern Chile the waters of the Cordillera only reach the sea north of Pisagua (Río de Lluta and Río Camarones, 19 ° lat. S.) and south of Caldera with the Copiapó and Huasco rivers (28 ° lat. S). In this stretch, over a length of about 900 km., The only real river of any importance is the Loa, which originates in the region of the Miño volcano, crosses the southern section of the Pampa del Tamarugal and flows into the sea between Iquique and Tocopilla after a course of 362 km. (a little less than the Tiber). To the north of the Loa, the waterways that arise from the Andes are lost in the eastern foothills of the Pampa del Tamarugal. To the south, the Atacama trench holds the waters that descend from the Puna volcanoes and are absorbed by the Salares. The Domeyko mountain range and the southern Pampas are equally poor in streams, while the Copiapó and Huasco owe to the abundant supply of the snows of the Andes if they never dry up completely. They swell in spring, in the period of snow melting.
As you proceed southwards the rivers increase in scope and importance: in the province of Coquimbo we have the 190 km long Río Elqui, at whose mouth La Serena has risen, and the Río Limarí (160 km.) it flows south of the Altos de Talinai. The Río Aconcagua is the main river in the province of Valparaiso that it crosses in all its width (length 170 km.): Its basin is very important because the Chilean section of the great Valparaiso-Buenos Aires railway artery develops in it. Further south runs the Río Maipó whose catchment basin almost entirely forms the province of Santiago: it is over 200 km long. and the capital of the state arose on the Mapocho river. Proceeding towards the south we meet the Maule (about 200 km), which bathes Talca and is navigable for a certain stretch by medium-range steamers; the Bío-Bío (362 km.), the largest river in Chile (v.bio – bio). Continuing towards the south we find rivers increasingly rich in water, both due to the more abundant rainfall and the more regular regime and because they are partly emissaries of lake basins fed by glaciers. Among these, the Tolten, emissary of the lake of Villarrica; the Calle-Calle, which bathes Valdivia; the Bueno (navigable for 80 km.), emissary of the Ranco lake (400 kmq.); the Maullín, emissary of Lake Llanquihue (740 sq. km.); the Palena, which flows into the Corcovado gulf; the Río de las Heras, which flows into the Golfo de Peñas and is an emissary of Lake Buenos Aires (1900 sq. km.), located between the Chilean and Argentine territories; il Toro, which also flows into the Golfo de Peñas and is an emissary of Lake S. Martín (940 sq. km.). Waterfalls are frequent. The numerous lakes of southern Chile (south of 39 ° lat.), at the western foot (and in Patagonia also at the eastern foot) of the Andes, they are, at least in part, of glacial excavation, and, like the great pre-alpine lakes, often represent cryptodepressions; these lake basins and the numerous glaciers that descend up to 700 meters high, often among magnificent coniferous forests, make the landscape particularly picturesque.