Existing climate data for Bolivian Amazonia rely on observations from a few sparse weather stations, interpolated on coarse-resolution grids. At the same time, the region hosts numerous indigenous groups with rich knowledge systems that are hitherto untapped in the quest to understand local climate change. Drawing on an empirical dataset of climate change observations by an Amazonian native society, we assess the potential use of indigenous knowledge for complementing available climate data. We find indigenous observations to be robustly associated with local station data for climatic changes over the last five decades. By contrast, there are discrepancies between gridded climate data and both indigenous observations and local station observations. Indigenous knowledge can be instrumental to enhance our understanding of local climate in data-deficient regions. Indigenous observations offer a tool to ground-truth gridded descriptions of climatic changes, thereby making adaptation strategies more robust at local scales. We contend that the use of indigenous knowledge could help to assist the climate interpolation process and address the prevailing uncertainties in local assessments of climate change.