Interior Climate: Much of the inside of South America is hot and often rainy. The Amazon Rainforest is very humid and has lots of rain. In some places, like the middle-west, it can be hot and rainy in the summer but dry and cooler in the winter. In others, like the Gran Chaco, it can be hot with not much rain.
Coastal Climate: Near the coast, the climate can be different. In some parts of the coast, like central Chile, it's mild with wet winters and hot, dry summers. In the Atacama Desert in Chile, it's super dry and hot. On the eastern coast of Brazil, it's warm and humid in the summer and not too cold in the winter.
Impact on Settlement: People usually settle more by the coast because the climate is better for living and farming. In the interior, it can be tough because of the extreme weather, like the rainforest's humidity or the dryness of places like the Gran Chaco. So, most cities and towns are near the coast because it's more comfortable to live there.