The climate of the La Plata Basin has experienced substantial decadal variability, as evidenced by both instrumental records spanning the past century and paleoclimatic reconstructions covering the past millennium. Additionally, in the subtropical region, a positive trend in rainfall has been detected in recent decades, superimposed on these low-frequency fluctuations. The decadal variability is primarily driven by the remote influence of large-scale oceanic processes in both the Pacific and Atlantic Oceans. In contrast, the observed long-term trend is attributed to human influence on climate, mainly through the increment in greenhouse gas emissions and stratospheric ozone depletion. The chapter provides a detailed characterization of regional climatic fluctuations on these timescales along with an analysis of the dominant large-scale mechanisms that drive this decadal variability. It highlights the most relevant global and regional climate trends and discusses the underlying physical mechanisms and their associated impacts. Furthermore, it explores the combined effects of natural climate variability and anthropogenic climate change in the basin, including future projections and their inherent uncertainties. The chapter concludes with a brief examination of the land-use changes in the basin and their implications for regional climate dynamics.