A stitch in time: district scale heatwave hazard, vulnerability and risk assessment in India

Abstract India experiences frequent and intense heatwaves due to climate change, threatening public health, infrastructure and livelihoods. Effective long-term adaptation to heatwave impacts requires a comprehensive assessment and characterization of heatwave risk, incorporating both hazard and vulnerability components. The present study analyses the changes in heatwave hazard for the past and recent periods, as well as heatwave vulnerability due to infrastructure, technology, financial, social, and exposure categories, followed by their sensitivities. It also provides a comprehensive district-scale heatwave risk assessment for India. The central, north-western, peninsular, and north-eastern regions of India have shifted from low to high levels of heatwave hazard, with 50.6% of the country’s districts experiencing a 40% or higher increase in heatwave hazard in recent years. Regions of central, eastern, and north-eastern India are found to be the most vulnerable, with financial access, public health infrastructure, cooling and mobility access primarily driving such vulnerability across the country. A bivariate choropleth heatwave risk assessment shows that the central and southern parts of India are hazard-driven, eastern and north-eastern India are predominantly vulnerability-driven. Regions of Telangana show a high-risk due interplay of high hazard and high vulnerability. These results highlight the importance of region-specific Heat Action Plans (HAPs) that address both climatic and socio-economic drivers of risk and do not adopt a one-size-fits-all strategy. This research complements the national HAP guidelines by providing detailed, actionable evidence to prioritise adaptive interventions in India’s most vulnerable districts.