The Amazon Basin is massive. It spreads over 2.7 million square miles. About 80% is forested with over 390 billion trees earning the moniker “the lungs of the earth.” To put this size into perspective, the lower 48 United States are 3.1 million square miles. The Amazon Rainforest is well named. On average, it receives 87 inches of precipitation a year over 200 days of rain. The wettest months are December through May. During this period, water levels can rise over 30 feet causing forests to flood. The hot dry season is September through November. The best time for visiting Floresta Amazônica (Portuguese) is in May and June.