In the twenty-first century, land use changes, massive expansion of urbanization, population growth, economic crisis, environmental issues are the main challenges of developing countries. Climate change and its effects on human health are the major concerns for the different age groups of the population. The study delved into the causes associated with climate change and climate change-related myriad health impacts on the study population. This study has used a concurrent mixed-method research design. The quantitative and qualitative data were collected from the study area. Perception and knowledge about climate change and its consequences on health was based on a quantitative approach of Bi-variate analysis and Chi-Square test and Fisher’s exact test; this study also used qualitative data analysis. Study results show that most respondents pointed out that temperature increases throughout the year and 90% of the respondents reported that rainfall pattern has also changed. Similarly, 65% of respondents agreed in their statements in favour of increased natural calamities in this region. The study findings show that more than 40% of population faces dengue fever and 10% of people also suffer from malaria. More than 60% of the urban population suffered from asthma. Similarly, more than 70% of the population also got affected by cold and cough due to weather variability. Focus Group Discussion (FGD) and In-depth interviews of the participants also affirmed the fact that climate variability induced diseases and health problems in Kolkata Metropolitan areas. Urban residents perceived that excessive urbanization contributes to the changes in regional climate and human health. The study will encourage the policy-makers and local government to mitigate adverse health effects driven by climate change in the Kolkata Metropolitan Region.