The ongoing climate crisis has highlighted the need for sustainability and resilience in the development and maintenance of urban areas regarding climate comfort. Weather simulation tools can aid researchers in understanding the effects that weather has on the microclimate in urban areas. While simulations are handled autonomously by computers once set up, the creation of the requisite input urban models is still a highly manual process. In this study, a novel method for the automated generation of urban models using land and cadastral remote sensing data is presented. By analyzing grass, trees, buildings, and roads algorithmically, data can be extracted and configured into spatial models compatible with microclimate simulation software such as ENVI-Met. Comparison to a baseline model shows that our method enables the creation of models fit for use for exploring microclimate scenarios in the urban environment, saving time by eliminating the need for manual processing.

This chapter interrogates the often-overlooked thermal consequences of building-integrated photovoltaic systems in Mediterranean coastal cities, where the pursuit of urban sustainability collides with the persistent challenge of outdoor thermal discomfort. Through advanced microscale climate simulations using the ENVI-met model, the study evaluates the influence of building-integrated photovoltaic installations on pedestrian-level thermal comfort in Limassol, Thessaloniki, and Naples. Despite the well-documented energy benefits of photovoltaic technologies, their capacity to reshape urban microclimates remains largely unsubstantiated in these southern European contexts. The findings demonstrate that building-integrated photovoltaic systems induce only minor thermal shifts, typically between 0.5 °C and 2.0 °C, that fall short of substantially improving thermal comfort or mitigating the urban heat island effect. Notably, these effects are geographically and morphologically contingent, with east–west street canyons exhibiting the most pronounced, albeit limited, variations. The research underscores that photovoltaic integration, while essential for energy transition, cannot singularly address the complexities of urban liveability in heat-stressed environments. Effective thermal resilience in Mediterranean cities demands integrated strategies combining energy technologies with vegetative, reflective, and shading interventions. By foregrounding this critical nuance, the chapter advances a more context-sensitive, human-centred approach to sustainable urban design. 

Due to climate change, the increase in electricity demand for building air-conditioning deserves comprehensive investigation during a hot and humid summer. This paper adopted the high-resolution version of the Max Planck Institute Earth System Model (MPI-ESM-1-2-HR) in Phase 6 of the Coupled Model Intercomparison Project (CMIP6) to generate future weather data based on three shared socioeconomic pathways (SSPs), namely SSP1-2.6, SSP2-4.5 and SSP5-8.5. A 1 km × 1 km resolution helped include the micro-climate effect. The resulting impact on a typical high-rise residential building in Hong Kong in the mid- (2040) and end- (2090) centuries was then analyzed. By choosing five district areas with different geographic natures, it was found that the cooling energy demand increased by 9 % and 29 % at most in the mid- and end-centuries. This corresponded to around 10.4 % per degree Celsius increase in the average ambient temperature. The demand was the highest in the district with a higher latitude. Different mitigation strategies were then applied through the modifications of the passive design, with five strategies yielding positive effects. The combined use of these five effective strategies could offer a tangible reduction in the cooling energy demand by at most 4 % as compared to the existing base case, even under SSP5-8.5 in the end-century. The results highlighted the strengths of these passive design strategies for cooling energy resilience under climate change for a sustainable future.

Microclimate research has seen significant growth in recent years, particularly in areas such as outdoor thermal comfort, urban ecology, and urban heat mitigation. However, the short-term nature of many studies in this field presents challenges in ensuring that the collected data accurately represents local climate conditions. This paper introduces a novel method to enhance the quality and applicability of microclimate research by quantifying the representativeness of short-term meteorological data. Our approach employs the Kolmogorov-Smirnov (KS) statistic to compare daily meteorological data from nearby stations against long-term climate trends. Key findings demonstrate that this method effectively identifies representative data periods. This method allows researchers to evaluate the representativeness of each day's data according to their specific study objectives, whether focusing on typical or extreme weather conditions. By implementing this framework, researchers can: (a) Post-filter existing data to identify the most representative samples. (b) Quantify the climate representativeness of their findings, enhancing result interpretation and applicability. (c) More confidently generalize conclusions from short-term studies. The paper also provides simplified alternatives to the full method, making it accessible to a wider range of researchers. By adopting this approach, microclimate studies can achieve greater confidence in their data's representativeness, leading to more robust and generalizable conclusions. Our method addresses a key methodological challenge in microclimate research and provides a flexible data assessment framework. This framework enables researchers to systematically evaluate climate data representativeness, enhancing the reliability and applicability of their findings across various urban climate studies, from thermal comfort assessments to climate adaptation strategies.

This article comprises nine ‘City Know-how’ briefings. Each designed to translate research findings into actionable insights for practitioners and communities who want to support urban health. Their purpose is to support the flow of knowledge for more effective action to promote and build health while reducing risks for human and planetary health. We hope they will foster connections and conversations between researchers, practitioners, policy-makers, communities, and decision-makers in cities.

Cities & Health, together with our ‘City Know-how’ partner, Building Health Lab, and our four global knowledge partners; invite communities, researchers, practitioners, and policy-makers to join our networks and contribute to the dialogue. You can access our interactive platform for ‘City Know-hows’ at www.cityknow-how.com.

Heat-health warning systems and services are important preventive actions for extreme heat, however, global evidence differs on which temperature indicator is more informative for heat-health outcomes. We comprehensively assessed temperature predictors on their summer associations with adverse health impacts in a high-density subtropical city. Maximum, mean, and minimum temperatures were examined on their associations with non-cancer mortality and hospital admissions in Hong Kong during summer seasons 2010–2019 using Generalized Additive Models and Distributed Lag Non-linear Models. In summary, mean and minimum temperatures were identified as strong indicators for mortality, with a relative risk(RR) and 95% confidence interval(CI) of 1.037 (1.006–1.069) and 1.055 (1.019–1.092), respectively, at 95th percentile vs. optimal temperature. Additionally, minimum temperatures captured the effects of hospital admissions, RR1.009 (95%CI: 1.000- 1.018). In stratified analyses, significant associations were found for older adults, female sex, and respiratory-related outcomes. For comparison, there was no association between maximum temperature and health outcomes. With climate change and projected increase of night-time warming, the findings from this comprehensive assessment method are useful to strengthen heat prevention strategies and enhance heat-health warning systems. Other locations could refer to this comprehensive method to evaluate their heat risk, especially in highly urbanized environments and subtropical cities.

The urban heat island (UHI) phenomenon presents pressing challenges for urban sustainability, intersecting urban planning, building design, public health and climate adaptation and mitigation policy. While UHI science has advanced, its knowledge and practice translation into real-life practice remains limited. This paper investigates the processes of how UHI knowledge can support the transition from diagnosing urban climate risks to shaping more thermally resilient cities. It begins by outlining the interdisciplinary significance of urban heat governance and highlights the persistent gap between scientific understanding and actionable outcomes by drawing from five global contexts—Japan, Germany, the United States, Hong Kong and Singapore. The paper explores how scientific insights are integrated into planning instruments, design regulations and environmental performance frameworks. Using an implementation science perspective, the paper examines four key themes: (i) barriers and enablers of science–policy integration, (ii) knowledge co-production, (iii) boundary objects and interfaces, and (iv) policy diffusion across cities. Findings emphasize the importance of institutional coordination, iterative co-production and simple and user-friendly tools for planners. The paper concludes by proposing a forward-looking research agenda focused on integrated modelling, climate-resilient design and community-driven approaches, contributing to a growing discourse on reorienting urban climatology towards practice for more equitable and sustainable cities.

The rising need for urban densification due to population demands and housing shortages has resulted in heightened interest in vertical extension (VE) of buildings. This paper presents a systematic review of 119 peer-reviewed articles analyzing VE research trends. The research employs content analysis, network visualization, and co-occurrence analysis to identify important terminology and definitions, thematic emphasis, and methodological approaches utilized in VE studies, across various temporal and spatial settings. The primary focus areas within the field are structural reinforcement, VE technologies, and suitability/impact considerations. Considering methodologies, the review demonstrates significant dependence on case studies and structural modeling to evaluate the feasibility and practical applicability. The study emphasizes the necessity for standardized VE taxonomy and recommends that future research should broaden its geographical scope to offer a thorough worldwide view on VE. The outcomes offer insights for urban planners, architects, policymakers, and academics, emphasizing key areas of attention and corresponding gaps.