Climate change is a harsh reality confronting the twenty-first-century world. It has been intensifying and leading to increased frequencies of extreme weather events day by day. As per the United Nations Environment Program (UNEP), extended periods of global climate change have led to extreme weather patterns, contributing to an increased likelihood of floods. Global warming poses a range of climate hazards, increasing the flooding vulnerabilities for coastal cities like Mumbai. Further, with the intensification of urban growth activities and the strong desire to live by the water bodies, the geological eventualities and flooding frequencies have been increasing in the cities of the global south. This study explores the vulnerabilities of extreme floods in the city of Mumbai due to climate change, and based on these analyses, we try to envision the city’s predicament in the context of urban sustainability. We use the PESTEL (i.e., Political, Economic, Social, Technological, Environmental, and Legal) framework to systematically evaluate the elements that influence flood resilience in Mumbai. Findings show that flood risks have increased more than in the past due to a combination of more extreme and unpredictable patterns of monsoon rainfall, ongoing sea-level rise, and human intervention. Residents of the informal settlements bear most of the impact of flooding risks due to their location in flood-prone areas and lack of resilient infrastructure. We recommend developing an integrated flood management policy and a multi-dimensional governance framework, aligning with the United Nations Sustainable Development Goals to resolve the issue.