Developing a baseline Heat Risk Index for the Humid Tropical city of Singapore

Singapore recognises the importance of addressing heat-related risks, particularly with temperatures set to increase against the backdrop of its humid tropical climate. Drawing from the IPCC’s definition of risk as a function of hazard, exposure, vulnerability, and response, this study presents the development of a baseline Heat Risk Index (HRI) for Singapore. Publicly available demographic, climatic, and geospatial data from 2018—including population census, vegetation, park spaces, infrastructure, and resources—are leveraged to build a comprehensive snapshot of the hazard, exposure and vulnerability parameters contributing to Singapore’s heat risk levels at that time. Responses – government policies and interventions – are documented, as the measurable effects of ongoing responses in and before 2018 would have been in part reflected in the hazard, exposure and vulnerability variables. This baseline would thus provide insights into geographic areas and populations that require additional support to address heat risks.  

However, the true value of the HRI lies in its capacity for regular updates. These updates would examine how heat-related risk evolves with future climatic and demographic conditions. By analysing active and measurable responses that would reduce future exposure, hazards, and vulnerability, the HRI would support evidence-based policies and offer insights into the effective responses in mitigating hazards, reducing exposure, and increasing adaptive capacities. By establishing this HRI baseline, the study lays the groundwork for a dynamic, living index that evolves with Singapore’s climatic and demographic landscapes, and support strategies in making Singapore adaptive and heat- resilient.