Urban overheating poses significant health risks to populations residing in urban areas. The rise in temperatures in urban environments can adversely affect human health in various ways. The heat stress caused by urban overheating manifests in an increase of heart rate, blood pressure, and the risk of cardiovascular events such as heart attacks and strokes. The impact of urban overheating extends beyond physical health to mental well-being. Addis Ababa, the capital city of Ethiopia, is facing a significant heat-health challenge due to the increasing impacts of heat exposure on its population. This study aims to develop an urban overheating vulnerability index for human health, to locate hotspots of vulnerable areas to pinpoint locations with heightened susceptibility to heat-related health risks, and to examine the spatially varying impact of urban overheating on public health. The study identified that the spatial epidemiology of urban overheating impacts the urban population unfairly and unevenly. Secondly, geographically weighted regression was used to explore the spatially varying impact of urban overheating on population health. Accordingly, the sub cities of Addis Kalema, Arada, and Lideta exhibit the highest vulnerability to urban overheating, with a significant population at risk. Gulelie, Nifas Silk, and Akaki Kality follow closely as the second most vulnerable areas in terms of heat hazards. Bole and Yeka are identified as the sub cities with the third highest vulnerable population in this context. The findings call for targeted public health interventions focused on areas with heightened vulnerability to urban overheating, including preparedness plans and community-based heat mitigation strategies. Public awareness campaigns are also required to educate residents about the health risks associated with urban overheating and the importance of adopting heat mitigation measures.