Iriri River Terra do Meio Ecological Station. The river varies greatly in volume depending on the season, and in the dry season include waterfalls, rocks and rapids. The Iriri River flows through the Tapajós-Xingu moist forests ecoregion. The river is rich in fish, including many species found only here and in the Xingu. Large sections remain unexplored due to its remoteness in a region surrounded by Amazon rainforest, and sections with strong current and cataracts. Iriri River The Iriri River () is a large tributary of the Xingu River in Brazil, in the state of Pará. It is long making it the
Xingu-Tocantins-Araguaia moist forests many smaller blackwater rivers including the Pacajá and Anapu tributaries of the Amazon River, the Bacajá and Fresco tributaries of the Xingu, and the Parauapebas and Catete tributaries of the Tocantins. The ecoregion is in the neotropic ecozone and the tropical and subtropical moist broadleaf forests biome. The Köppen climate classification is "Am": equatorial, monsoonal. Temperatures are fairly steady throughout the year, slightly higher in April and slightly lower in July. Average temperatures range from , with a mean of . The region is drier than the ecoregions further to the west. In the middle Xingu annual rainfall is .