The plains are low and flat, most of which are below 150 meters above sea level, so there are winding rivers and many lakes. Rainy, humid and continuously high temperatures are its notable climate characteristics.

Due to the rainy areas near the equator, the Amazon has abundant water all year round. The average annual flow rate at the mouth of the Amazon River is 220,000 cubic meters per second, making it the river with the widest basin and the largest flow in the world. Brazilians proudly call it the "River Sea". It is estimated that about 20-25% of all the water flowing on the earth's surface is in the Amazon River.