The climate across South America varies widely, from the driest desert on Earth (the Atacama) to the largest tropical rainforest (the Amazon), and from the lowest point in the Western Hemisphere (Laguna del Carbon) to the highest (Mount Aconcagua). Much of South America, however, lies in the tropics.
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere and the Tropic of Capricorn in the southern hemisphere; these latitudes correspond to the axial tilt of the Earth. The tropics include all the areas on the Earth where the Sun reaches a point directly overhead at least once during the solar year. About 40 percent of the world’s population lives within the tropical zone (by 2008 statistics), and it is estimated that by 2060, 60% of the population will be in the tropics, owing to high birth rates and migration.
The climate of South America can be broadly divided into seven different climate types:
- Desert: Warm to high temperatures with very little rainfall.
- Grassland: Hot summers and cold winters with above average rainfall.
- Deciduous forest: Four distinct seasons with warm summers and cold, wet winters. The trees shed their leaves in autumn.
- Rainforest: High temperatures and high rainfall throughout the year.
- Savanna: Very high temperatures all year and rain during the summer season only.
- Mediterranean: Warm to high temperatures with rainfall in the autumn and winter months.
- Alpine/mountain: Cold, windy, and snowy. It is winter from October to May with temperatures below freezing, whereas summer is from June to September and the temperature can reach upwards of 59°F (15°C).