When to go by area
Whilst hot and humid all year round, there is a dry season in the Amazon between June and December, whilst the wetter season runs from December to May. You may experience some heavy tropical downpours in the afternoons, but these provide welcome respite from the humid conditions. In terms of wildlife, the drier months, in particular between July and late October are best for bird watching and seeing the land mammals and butterflies in the drier forest.
The Pantanal wetlands have a rainy season between December and March and a drier season between May and October. Generally the dry season offers the best opportunity to see the mammals, reptiles and birds of the Pantanal, who congregate at watering holes. If you wish to track the elusive jaguar in its natural habitat on an exciting safari through the rivers of the Pantanal, the optimum time for this is June through October.