Analysing Surface Urban Heat Island risks: mapping the vulnerability of dwelling and dwellers across Swedish municipalities

Sweden’s average temperature has increased by 1.9 °C since the late 19th century and is projected to rise by another 3–5 °C by the end of the century. As urbanisation amplifies heat stress, there is an urgent need to assess Surface Urban Heat Island (SUHI) risks, especially in high-latitude regions like Sweden, where such studies are limited. This study maps SUHI hazards, exposure, and vulnerability across Sweden to identify high-risk municipalities, focusing on residents in Single-Family Houses (SFHs). MODIS-derived land surface temperature (LST) data (2015–2022) were used to estimate SUHI intensity (hazard). Population density and building footprint data informed exposure, while vulnerability was measured using a Composite Vulnerability Index (CVI) based on social and physical indicators, including population demographics and building-related characteristics. All indicators and risk components were normalised, weighted using entropy and PCA, and integrated through geospatial analysis to produce a 1 km resolution national SUHI risk map, validated using heat-related mortality data. Results indicate that high-risk areas are concentrated in major cities. 12 high-risk municipalities contain 14 % of all SFHs built before 1975, and 18 medium-risk municipalities contain 8 %, together accounting for 22 % of the national pre-1975 SFH stock. Residents of these SFHs represent nearly half of those living in pre-1975 SFHs nationwide. These findings highlight the urgent need for climate-smart renovations with strategies like reflective roofing, increased greenery, and soft financing for urban adaptation planning in northern climates.

• surface urban heat island
• heat risk mapping
• heat vulnerability
• single-family house
• land surface temperature
• composite vulnerability index
• heat-related mortality
• climate change adaptation
• Sweden

• 11 — Villes et communautés durables
• 13 — Mesures relatives à la lutte contre les changements climatiques

• Urban Heat Island Mitigation
• Climate Change and Health Impacts
• Environmental Justice and Health Disparities
• surface urban heat island
• heat risk mapping
• heat vulnerability
• single-family house
• land surface temperature
• composite vulnerability index
• heat-related mortality
• climate change adaptation
• Environmental Engineering
• Health, Toxicology and Mutagenesis
• Sociology and Political Science
• Environmental Science
• Social Sciences