The annual march of rainfall in the Amazon Basin (Fig. 2) displays a great spatio-temporal heterogeneity as it goes by. The wet season during the winter and spring months (DJF-MAM) sees an immense amount of rainfall spreading through the entire Basin as the Intertropical Convergence Zone (ITCZ) begins its movement to the south of the region and the moisture transport from the Tropical North Atlantic ocean gets more intense.  This season is also characterized by a huge moisture transport from the Basin itself to the South-Southeast region of Brazil and Argentina by the so-called Atmospheric Rivers, which are also formed in the region.
This huge rainfall, however, is replaced as the dry season starts in summer months. The southernmost part of the Basin suffers from reduced water levels and lack of rainfall as the northernmost part still gets heavy precipitation events, especially in the region known as the Dog's Head. This region is possibly the wettest in the entire South American continent as it practically has no seasonality and year-long rainfall levels.    
The start of the dry season is followed by the start of the fire season in the southern portions of the basin, concentrated mostly in the Arc of Deforestation in Brazil. Although there are also fire occurrences during the wet season and the use of fire is a cultural aspect of the indigenous peoples in Amazonia, the highest numbers are found in the dry periods because the lack of rainfall provides a window of opportunity for the (mostly illegal) advance of the agricultural frontier. One of the consequences of extreme drought events in the region is precisely the increase of this window of opportunity for fire occurrences, as happened during the 2015/2016 strong El NiƱo event.