Hydroclimate combines hydrology and climate variables, including the influence of water resources and their processes on Earth’s climate pattern and the change in the hydrological cycle. This review aimed to investigate the historical, current, and future projections of hydroclimatic variables within the Awash River basin. The spatiotemporal climate fluctuations caused by meteorological anomalies, catchment topographical processes, and human activities impact hydroclimatic variables. This systematic review was conducted to define and conceptualize hydroclimatic variables’ trends and variation. Scopus, Web of Science, and Google Scholar were used to assess relevant works of literature. Most of the rainfall stations in the basin exhibited an increasing and decreasing trend; however, this was not statistically significant. The mean, maximum, and minimum temperature variables continuously increased in the basin while streamflow declined. Besides, hydroclimatic variables and trends in response to climate change differ by local topography, length of data and statistical methods. Additionally, the basin encounters various trends and patterns in hydroclimate variables over time. This review emphasizes the importance of historical, current, and future climate change scenarios in the development of water resources and practices for sustainable environmental management. As a result, reviewing the findings provides a scientific basis for evidence-based practice for environmental and water resource managers, researchers, and policymakers.