Brownish elaenia the Xingu River in the south of Pará state, North Region, Brazil; it ranges upstream on the Xingu for 700 km, then a tributary to the west of the Xingu, the Rio Iriri, for another 700 km. The next upstream tributary for the bird's range, is the Madeira River in the Amazon Basin's southwest, Amazonas state. The range proceeds 2400 km upstream into the headwaters of the Madeira in northern Bolivia. To the west the brownish elaenia's range continues as the Amazon River becomes the Marañón River and proceeds to the headwaters in northern Peru; this is also along 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 .