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Present-day and projected future changes in mean radiant temperature, T mrt in one northern, one mid-, and one southern European city (represented by Gothenburg, Frankfurt, and Porto), are presented, and the concept of hot spots is adopted. Air temperature, T a, increased in all cities by 2100, but changes in solar radiation due to changes in cloudiness counterbalanced or exacerbated the effects on T mrt. The number of days with high T mrt in Gothenburg was relatively unchanged at the end of the century (+1 day), whereas it more than doubled in Frankfurt and tripled in Porto. The use of street trees to reduce daytime radiant heat load was analyzed using hot spots to identify where trees could be most beneficial. Hot spots, although varying in intensity and frequency, were generally confined to near sunlit southeast-southwest facing walls, in northeast corner of courtyards, and in open spaces in all three cities. By adding trees in these spaces, the radiant heat load can be reduced, especially in spaces with no or few trees. A set of design principles for reducing the radiant heat load is outlined based on these findings and existing literature.

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<p>Climate change and social-economic development are expected to compound climate changes risks. For southeast Asian cities, the occurrence of urban heat islands and extreme heat waves are a current and future concern for public health, well-being and household energy consumption due to increased cooling demands of urban residents and limited resources to cope. Urban heat island studies using remotely sensed imagery have already revealed that Vietnam’s major cities are characterized by strong temperature differences between urban and rural areas. As such implementing adaptation measures is paramount to limit adverse impacts of heat on urban inhabitants. While different adaptation measures are currently debated by the political authorities in Vietnam, decision-making is hampered by multiple scientific knowledge gaps and the lack of practical tools to support decision-making. This paper presents an approach to investigate the pattern and characteristics of the urban heat island in Can Tho City, located in Vietnam’s Mekong Delta. This study investigated the relationship between urban heat with urban structure types, building density and blue and green spaces. An urban structure type approach was used to classify and partition the city into spatial units of different types of buildings (housing archetypes, functions, infrastructure), degrees of planning (regular, irregular), densities and open spaces on the official block geometry of the official land use plan and linked to remotely sensed land surface temperatures. The results in the form of a series of risk analysis maps at a planning relevant scale, confirm the effects of land uses and urban structures on local temperatures and allow policy makers and planners to better understanding of the relationship between the urban temperatures, functions and densities in order to reduce the UHI and promote more sustainable and resilient urban development.</p>

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