Urban heat island in the tropics: A review of advances, challenges, and future directions

Urban Heat Islands (UHI), characterized by elevated temperatures in urban areas compared to their rural surroundings, represent a growing concern in the context of climate change, particularly in tropical regions. While UHI research has advanced significantly in temperate zones, tropical climates have received comparatively less systematic attention, despite their high vulnerability to global warming and rapid urbanization. This review systematically analyzes UHI studies conducted in tropical contexts between 2000 and 2024, using the PRISMA methodology. A total of 508 documents were identified through Dimensions.ai using search terms such as “Urban Heat Island” AND “Tropical” or “Tropics”. After screening and eligibility assessment, 156 studies were included. The review covers experimental and numerical approaches, remote sensing methods, and solution-oriented strategies across multiple urban scales. The term ”tropics” here encompasses regions located between the Tropic of Cancer and the Tropic of Capricorn, although considerable climatic, socio-economic, and geographical diversity exists within this band. Our findings highlight a concentration of research in large metropolitan areas, with medium and smaller cities often overlooked. The lack of microclimate or neighborhood-scale and multiparameter analyses limits our understanding of localized UHI dynamics and the applicability of mitigation strategies. We identify the need for more holistic, interdisciplinary approaches that integrate diverse climate parameters and locally validated models tailored to the combined complexity of tropical climates and urban environments. Expanding UHI research in underrepresented regions and adopting multiscale strategies are crucial for advancing inclusive, climate-resilient urban planning in the tropics.