Chile's mainland territory extends from 17º30' to 56º30', beginning at the altiplano and ending at the southernmost islands in the world at Tierra del Fuego.
On the map, Chile looks like a long, narrow strip of land, with a length of over 4,000 kilometers and an average width of 177 kilometers. In the country's northern region, the altiplano and deserts predominate, including the Atacama Desert, the most arid on the planet. In the central region, the country's two dominant mountain ranges – the Cordillera de la Costa (Coastal Mountain Range) and the Andes – create a series of valleys lined with fast-flowing rivers and an abundance of farm land. The country's southern region runs from latitude 38º south to 41º and is known for its large lakes, evergreen forests and snow-capped volcanoes. The region is also home to important inter-oceanic passages like the Strait of Magellan, the Beagle Canal and the Drake Passage.
Due to the shape of its territory, Chile possesses 4,000 kilometers of coastline, laden with extensive beaches and towering cliffs hanging over the sea. To the east, and parallel to the Pacific, you'll find the Andes, which feature some of the highest peaks of the entire mountain mass, including Ojos del Salado Volcano (6,893 meters), the Llulaillaco Volcano (6,739 meters), Tres Cruces (6,749 meters) and Cerro Tupungato (6,635 meters).
In the country's central region, the peaks of the Cordillera de la Costa impede the flow of the marine climate, and the wall formed by the Andes seals off continental influences. The presence of the sea gives the country a predominantly Mediterranean-style climate, with moderate temperatures and a wide range between the highs of the day and the lows of the night, creating fog and cool winds, the latter even more a product of the cool Humboldt Current.
The southern region has more humidity and precipitation and lower temperatures than the central region, while northern Chile features a dry desert climate, hot during the day and very cold at night.
The climatic diversity can be observed through the frequency of rainfall, which becomes considerably more pronounced as you head south. The rainy season also varies by region. On the altiplano, it comes during summer and from the central region to the Patagonia, in the winter.
The situation is the same when it comes to the highs and lows in temperature. It is warmer in the north and central regions, and gets colder as you head south. Chile has four well-defined seasons. All of Chile's cities experience their warmest weather between October and April and the coldest from May to September.
Norte Chico ("Little North," from the latitudes 26º to 33º south, approximately from the city of Vallenar to Illpel): With a warm steppe or semi-arid climate, a transition from the desert climate of the northern region to the colder climates of the south, Norte Chico features irregular rains that mainly come during the winter. On the coast of the Coquimbo area, you'll find a coastal steppe climate, with more precipitation than Norte Grande. This is due to the significant environmental humidity that manifests itself in the form of thin fog and light rain. In La Serena, the average annual temperature is 14.7ºC. In the valleys, the climate features less environmental humidity and higher temperatures (between 19ºC and 20ºC).
Central Region (from 33º to 37º south, approximately from the city of Illapel to Los Angeles): Chile's Central region has a Mediterranean climate. In this part of the country, the climatic conditions are more moderate, combining a considerable amount of precipitation with a greater range of distribution of the rain. The rains tend to fall during winter and the climate is dry and temperate in summer. The seasons are well-differentiated in this part of the country, with the cold season running from May to September and the hot season lasting from October to April. On the coast, the variations are softer, while inland cities like Santiago features more extreme swings, most notoriously in winter (an average of 8ºC). The average temperature in summertime is 20ºC, with highs above 32ºC.
Southern Region (from 37º to 41º south, approximately from the city of Los Ángeles to the archipelago of Chiloé): Southern Chile features a temperate rainy climate on the coast and inland areas, with frequent precipitation and temperate-to-cool temperatures. It's a transitional climate between the Central Region and the Patagonia. Cities like Concepción and Valdivia receive an average of 2,600 mm of rain a year. The cold increases as you travel south, as does the humidity, due to the proximity of the Pacific Ocean (maritime climate). In Concepción, the average summer temperature is 17ºC with little rain (which becomes more frequent between May and August). Temuco, Valdivia and Osorno are rainy cities, with an even more pronounced Mediterranean climate. Chiloé is home to areas that receive more than 4,000 mm of precipitation a year. The mountain region features very low temperatures and receives abundant snowfall in the winter.
Patagonia Norte ("Northern Patagonia", from 41º to 46º 30'', starting from the city of Puerto Montt, including all of northern Patagonia, until the town of Cochrane, approximately): Due to its extensive size, this area presents significant climatic variations influenced mainly by the relief, the sea and the winds. Near the Carretera Austral and the region of Aysén, there is a low-temperature maritime climate, with abundant precipitation, strong winds and humidity. The characteristics of relief create a difference in climate in the eastern sector of the Patagonian Andes, where the climate is tundra, less rainy and colder (with an average temperature of 7ºC in its northern sector and a cold steppe climate towards the east, featuring less precipitation, strong winds and snow in winter).
Patagonia Sur ("Southern Patagonia", from 46º 15'' to 56º 30'' south, from Cochrane to Punta Arenas and Tierra del Fuego, approximately): In the southernmost sector of the continent, near Punta Arenas, a cold steppe climate predominates in the central continental area. The average annual precipitation is 425 mm, which falls as rain mainly in spring and summer and as snow in winter. The wind is constant here, becoming more intense during spring and summer, when it reaches an average speed of 30 to 40 kilometers an hour, with maximum speeds of 100 kilometers an hour. The winds let up almost entirely during the winter. The average winter temperature is 2ºC, and the average summer temperature is 10.6ºC.