The average rainfall in the Amazon rainforest is about 108 inches per year. The high amount of rain combined with a warm year-round climate makes the Amazon rainforest the most biodiverse place on Earth.
The Amazon rainforest gets its name from the Amazon River. It starts in the Peruvian Andes and spans the northern half of South America. The Amazon River is about 4,080 miles long and has many tributaries, making it the largest river system in the world.
The soil in the Amazon is poor because the high rainfall causes minerals to drain away. Despite this, trees in the rainforest canopy can grow to over 150 feet tall. Falling leaves and branches constantly add nutrients to the soil so that new plants and trees can grow.