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Collaboration is strongly promoted as an effective means for cities to respond to climate change. While collaboration is perceived to offer opportunities to progress climate action in cities, little is known about how collaboration can enable low‐carbon transformation in practice. Furthermore, while collaboration is largely framed as a positive endeavour, there is a need to more carefully explore the challenges and barriers that may arise. This paper explores the aims, processes, and outcomes of collaboration within urban climate governance. Drawing on a policy review and semi‐structured interviews, we present empirical findings from the case study of Hong Kong. This paper identifies three types of collaboration that are structured by regulations, oriented to policy goals, and emerge as everyday practices within the governance of climate change and the energy system. The forms of collaboration challenge the assumptions that collaboration always brings positive outcomes in mobilising action for climate change. While collaboration opens up different modes of governance within cities, the paper highlights significant barriers in terms of the diverse roles of actors, ongoing power imbalances, and shifting governance spaces for intervention. Given the prevailing interest in working together, it is critical to review carefully how collaboration facilitates cities to achieve their climate goals and create momentum for action. The paper explores the opportunities and challenges of collaborative climate governance. It draws on a case study of Hong Kong and identifies three modes of collaborative climate and energy governance: regulatory, consensual, and participatory. The paper challenges the assumption that collaboration brings positive outcomes for action on climate change and offers new insights into potential barriers for climate action in cities. [ABSTRACT FROM AUTHOR]

The role of cities in mobilising transformative change has gained increasing attention in global discourses on climate change and sustainability. Through the lens of urban energy transitions, this paper focuses on how this form of change within the urban energy system can be mobilised. Capacity is an emergent concept and has been adopted to identify areas for change and assess the transformative potential of cities. Connecting three dimensions of capacity: capacity for what, capacity of whom and the process of capacity building, we present a new conceptual framework to understand diverse transition pathways. To interrogate the capacity framework in practice, we explore the illustrative cases of Hamburg and Hong Kong. The paper demonstrates that capacity is connected to specific changes in political, material, institutional and other energy‐related societal contexts. Understanding the variety of dependencies and underlying challenges within urban energy systems , as well as the kinds of actor coalitions that are capable of addressing such complexity and mobilising change, enables the development of specific socio‐technical solutions for urban energy transition pathways. Our focus on local capacity to act and how such capacity can be expanded or diminished contributes to a deeper understanding of the power relations embedded in urban energy systems and the role local actors can play in enabling and hindering processes for change. Such examination of how complex trajectories for change are defined and shaped allows significant insights into plausible futures of urban development. [ABSTRACT FROM AUTHOR]

The combined impacts of COVID-19 and global climate change are destabilising the infrastructures and future prospects of formal educational systems, with schools and universities struggling to adapt to conditions of radical precarity. At the same time, activist movements are generating alter-educational platforms that reappropriate the learning infrastructures of cities as mobile architectures of pedagogical resistance. Building on Harney and Moten's The Undercommons, this paper discusses transnational examples of radical pedagogies that engage the city as an ecology of deformalised study. We highlight examples from Melbourne's COVID-19 lockdown regime, emphasising how informal study enabled community-led responses to crisis at city-scale. We then turn to urban ecologies of study arising from contemporary activist movements, drawing connections between protest movements in Hong Kong and Deleuze and Guattari's concept of the 'war machine'. This leads to a speculative re-imagining of alternative educational values and futures within a milieu of activist study, care, and resistance. [ABSTRACT FROM AUTHOR]

The combination of dense urban development, hilly terrain, and intense seasonal rainfall has caused acute landslide problems in Hong Kong, which are manifested by a death toll of over 470 people since the late 1940s. Tackling landslide problems in an urban setting, in particular under the effect of climate change, calls for a development and implementation of a holistic risk management strategy. It entails the use of engineering and non-engineering approaches, involving policy, legislative, administrative, innovation, technical, educational, community-based, and emergency-preparedness provisions. In this paper, these two approaches are showcased by the slope safety system that has been developed and promulgated in managing landslide risk for building Hong Kong as a world-class smart city. [ABSTRACT FROM AUTHOR]

• The proposed tropical cyclone model is completely driven by a set of environmental variables. • This model reproduces the spatial and temporal characteristics of observed tropical cyclones. • The model achieves remarkable balance between computational complexity and efficiency. • This model will provide decision-makers with valuable information regarding potential wind-induced hazards. • When future climate data are fed into this model, the impact of climate change on tropical cyclones can be evaluated. This paper presents an environment-driven tropical cyclone (TC) model for the Western North Pacific basin, which comprises a revised Poisson regression genesis model, a tailored beta-advection track model, and a fast intensity model. The TC model reproduces the temporal and spatial distributions of genesis events, the motion pattern of tracks, as well as the intensity evolutions along tracks. Risk analyses for Hong Kong and along the southeast coastline of mainland China demonstrate that this model can simulate extreme TC events with high fidelity. And the Gaussian mixture model outperforms the Frank Copula in approximating the joint distributions of the annual maximum wind speeds and the corresponding wind directions. This model is driven by a set of environmental variables including relative vorticity, relative humidity, sea surface temperature, vertical wind shear, potential intensity, sub mixed layer depth stratification, mixture layer depth and so on. This enables the model to not only reproduce historical records, but also make predictions for future TC behaviors under climate change with combination of global climate models. Besides, the computational efficiency of the TC model is comparable to traditional purely statistical models. The proposed model can also be coupled with other natural hazard models to conduct multi-hazard analysis. [ABSTRACT FROM AUTHOR]

Radiative cooling coating technology is gaining increasing attention in the context of mitigating urban heat island and tackling global climate change. This paper is concerned with the development of an inorganic geopolymer-based radiative cooling coating using red mud, incorporating varying sizes of TiO 2 and hollow glass beads. The developed colored coating demonstrates its radiative cooling capability in reducing the surface temperature by harnessing the potential of red mud. The physico-chemical properties, surface morphology, and element distribution of the coating were characterized by XRD, FTIR, TG-DAT, SEM and EDS. The coating exhibited lower UV (0.0844) and visible reflectance (0.5275) but high NIR reflectance (0.7536), as well as high infrared emissivity of 0.9455, enabling a red color with a CIE value of L* = 74.56, a* = 9.55, and b* = 11.98, and a maximum temperature reduction of 7.3 °C under the climate of Hong Kong. Additionally, the skid resistance, abrasive resistance and adhesion strength of the proposed coating could meet the requirements of standards, indicating a great potential for footway applications. [ABSTRACT FROM AUTHOR]

Vertical greenery not only helps to cool the surfaces of buildings but, more importantly, it can also mitigate the Urban Heat Island effect. The growth of vertical greenery is highly dependent on ongoing maintenance, such as irrigation. Wind-driven rain serves as a natural source of irrigation for vertical greenery. Wind-driven rain simulation was conducted on a typical high-density and high-rise case in Hong Kong to first classify the wind-driven rain harvesting potential on the façade with very high, high, moderate, low, and very low levels. Then, Scenario 1 (very high potential), Scenario 2 (very high + high potential), and Scenario 3 (very high + high + moderate potential) regarding vertical greenery in locations with three levels of wind-driven rain harvesting potential were simulated in ENVI-met to assess its Urban Heat Island mitigation effect. The maximum temperature reduction on the street occurs between 12 p.m. and 3 p.m., indicating the greatest mitigation of the Urban Heat Island effect. Scenario 1, Scenario 2, and Scenario 3 achieve a maximum temperature reduction of 0.76 °C, 0.88 °C, and 1.06 °C, respectively, during this time period. [ABSTRACT FROM AUTHOR]

Aim: The capacity for poleward range expansions beyond the tropics in corals hinges on ecophysiological constraints and resulting responses to climatic variability. We aimed to determine how future warming will affect coral habitat suitability at the poleward range edges of these foundational species in the Northwest Pacific. Location: Northwest Pacific. Methods: We generated models integrating thermal physiological constraints of corals adapted to extreme seasonality in Hong Kong, specifically the minimum annual temperature and the proportion of time annually spent at seasonal extremes. With these models, we projected habitat suitability for five coral species under current and future climatic conditions across the Northwest Pacific. Results: Climate model projections reveal an easing of thermal constraints on the leading‐edge of coral ecophysiological limits with an expansion of thermally suitable habitat poleward by 2°–7° in latitude depending on the coral species and model considered. We also highlight a potential divergence of present and future thermal regimes that may lead to a mismatch in suitability for corals currently inhabiting high latitude reefs. Main Conclusions: Understanding the thermal constraints on coral distributions and defining the potential range of corals under climate change is critical for adaptive management that focuses on coral conservation and ensuring ecosystem function of existing subtropical and temperate ecosystems. [ABSTRACT FROM AUTHOR]

Carbon emission trading mechanism is an important market-based instrument to address global climate change. The auction ratio and price of carbon emission allowances (CEA) are cores of the carbon emission trading mechanism. What combination of CEA auction ratio and auction price is most conducive to carbon emission reduction for emission control enterprises? There are still relatively few studies conducted on this issue, and there is no clear answer from the views of theory and practice. In this paper, the AIM/Enduse model was used to analyze the changes and differences of installed power capacity, power supply, energy consumption and carbon emissions in the Guangdong-Hong Kong-Macao Great Bay Area (GBA) with different combinations of CEA auction ratios and prices. Moreover, the best pathway of energy transition was explored in the power industry of the GBA, and the best combination of CEA auction ratios and prices was identified in the GBA. The results show that: (1)The carbon emission constraint starts to work only when the auction ratio of CEA is increased to 50% and the auction price is increased to 60 CNY/ton (Scenario p 3). When the auction ratio of CEA is 100% and the auction price reaches 120 CNY/ton (Scenario p 5), a low-carbon transition of the power sector in the GBA can be achieved. (2) Under scenario p 5 , the total cost of power transition rises and then falls. And the cost of carbon in the power sector increases exponentially as the auction ratio of CEA and the auction price rise. However, the growth in the cost of power supply is relatively flat, which shows that appropriate carbon trading mechanism can improve the economic benefits of power sectors. With the increase of installed capacity of clean low-carbon energy generation and power supply, as well as the decrease of local power cost in the GBA, the proportion of outsourcing power can be appropriately reduced in the future, with an aim to reduce the external dependence of electricity to ensure the security of energy supply. In the end, it suggests that cities in the GBA should give full play to their regional advantages and establish a unified carbon emission trading market in the GBA as soon as possible. This study provides a theoretical basis for the supplementation and improvement of China's carbon emission trading mechanism. • What is the best combinations of CEA auction ratios and auction prices in the GBA? This paper gives a clear answer. • The best transition pathway of the power industry under technological progress and carbon trading policy was suggested. • With the decrease of local power cost, the proportion of outsourcing power can be appropriately reduced in the future. • Provides a theoretical basis for the supplementation and improvement of China's carbon emission trading mechanism. [ABSTRACT FROM AUTHOR]

Maritime transport contributes to the exacerbation of global warming, which is responsible for several environmental issues. Since Hong Kong (HK) is recognized as one of the largest shipping registries in the world in terms of gross tonnage and its port is very busy, to examine the regulatory and policy measures adopted, and to discuss the need for introducing additional policy measures for controlling marine Greenhouse Gas (GHG) Emissions in HK is both necessary and important. This article accordingly investigates the current policy and regulatory measures controlling marine GHG emissions in HK, and confirms that HK implements the relevant international treaties; HK has meanwhile been working together with mainland China, particularly with cities in the Greater Bay Area (GBA), to combat air pollution. This article also highlights the main problems and issues associated with HK's existing measures, and then discusses the way forward. It concludes that the current measures in HK are far from satisfactory, and that there is an apparent need to improve them so as to more effectively control marine GHG emissions. [ABSTRACT FROM AUTHOR]

The importance of monitoring sea level in coastal zones becomes more and more obvious in the era of global climate change, because, in coastal zones, although satellite altimetry is an ideal tool in measuring sea level over open ocean, but its accuracy often decreases significantly at coast due to land contamination. Although the accuracy of waveform processing algorithms for synthetic aperture altimeters has been improved in the last decade, the computational speed is still not fast enough to meet the requirements of real-time processing, and the accuracy cannot meet the needs of nearshore areas within 1 km from the coast. To improve the efficiency and accuracy in the coastal zone, this study proposed an innovative waveform retracking scheme for the coastal zone based on a multiple optimization parabolic cylinder algorithm (MOPCA) integrated with machine learning algorithms such as recurrent neural network and Bayesian estimation. The algorithm was validated using 153-pass repeat cycle data from Sentinel-6 over Qianliyan Island and Hong Kong–Wanshan Archipelago. The computational speed of the proposed algorithm was four to five times faster than the current operational synthetic aperture radar (SAR) retracking algorithm, and its accuracy within 0–20 km from the island was comparable to the most popular SAMOSA+ algorithm, better than the official data product provided by Sentinel-6. Especially, the proposed algorithm demonstrates remarkable stability in the sense of proceeding speed. It maintains consistent performance, even when dealing with intricate wave patterns within a proximity of 1 km from the coast. The results showed that the proposed scheme greatly improved the quality of coastal altimetry waveform retracking. [ABSTRACT FROM AUTHOR]

Coastal ocean acidification is a worldwide problem associated with anthropogenic activity and climate change. In this study, a close relationship between submarine groundwater discharge (SGD) and coastal ocean acidification in Hong Kong's coastal waters is discovered. We for the first time evaluated the direct influence of SGD on seawater pH decline. Results show that SGD can contribute to up to 48% of seawater pH variation among terrestrial water input, air‐sea CO2 exchange, photosynthesis/respiration, and bay‐open water exchange in semi‐closed bays through direct input of carbonate species. Local air‐sea CO2 exchange has negligible influences on the seawater pH. In the semi‐closed bay areas, SGD and aerobic respiration are major contributors to seawater pH variation but in areas with open space, the exchange process with open waters is more important. In addition to the direct input of carbonate species (total alkalinity and dissolved inorganic carbon), SGD also influences the seawater pH via considerable nutrient loadings. The findings highlight the importance of the investigation and management of groundwater to alleviate the fast coastal ocean acidification. Plain Language Summary: Seawater becoming more acidic is a big problem in coastal areas around the world due to climate change. The main causes of this acidification are excessive nutrient release and human‐generated carbon dioxide. When groundwater flows into coastal areas, it carries chemicals from the land that can affect the pH of the seawater. In our research, we discovered that groundwater releases more dissolved inorganic carbon compounds, which lower the seawater's pH, compared to the total alkalinity that normally helps maintain a stable pH. Groundwater is a major factor in causing acidification in semi‐closed bays along the coast. We want to emphasize the importance of understanding the impact of coastal processes and managing groundwater in order to slow down the acidification of coastal waters. Key Points: Submarine groundwater discharge (SGD) strongly correlates with long‐term ocean acidification rates, unveiling their significant relationshipSGD accounts for ∼50% of seawater pH decline in semi‐closed bays, primarily through direct carbonate species inputSGD indirectly impacts seawater pH decline by influencing aerobic respiration processes, amplifying its role in pH dynamics [ABSTRACT FROM AUTHOR]

Summary: Tall buildings located in Hong Kong can suffer great damage caused by typhoon hazards throughout their lifetimes. In addition, the effect of wind hazards may be exacerbated due to increases in the typhoon intensity and frequency caused by the climate change effect. Therefore, developing a framework to evaluate and quantify the damage caused by wind hazards on tall buildings from the economic perspective is critical for engineers and building owners in designing a cost‐effective tall building. In this study, an economic damage indicator, life‐cycle cost, is measured by using a probabilistic method called life‐cycle cost analysis (LCCA). Moreover, the building sector is one of the biggest contributors to greenhouse gas (GHG) emissions, and the environmental impact that may be generated in intervention activities after wind‐induced damage occurs is analyzed. An environmental impact indicator, embodied carbon emission, is quantified by employing another probabilistic method called life‐cycle assessment (LCA). Therefore, an integrated methodology combining the LCCA and LCA is proposed to evaluate potential damage costs and environmental impact caused by typhoon hazards on tall buildings. [ABSTRACT FROM AUTHOR]

The growing interconnectedness of urban infrastructure networks presents challenges to their ability to handle unforeseen disruptions, particularly in the context of extreme weather events resulting from climate change. Understanding the resilience of interconnected infrastructure systems is imperative to effectively manage such disruptions. This study investigates the role of interconnectedness in enhancing the resilience of public transportation systems in Hong Kong, a city heavily reliant on public transit. Our results demonstrate that interconnected transportation systems improve resilience by reducing topological vulnerabilities, increasing attack tolerance, and enhancing post-disruption interoperability. Findings also identify the potential to integrate vulnerable systems for greater robustness and highlight the marginal benefits of enhancing intermodal transfer. Strengthening interconnectedness among modes of urban public transit fosters a safe-to-fail system, presenting a distinct resilience-by-design approach. This complements conventional resilience-by-intervention approaches that focus on improving individual systems or introducing entirely new systems. The growing interconnectedness of networked infrastructures has a complex impact on resilience in urban environments. Xu and Chopra quantify these effects using network resilience analysis and highlight the benefits of topological interconnectedness within multimodal public transportation systems. [ABSTRACT FROM AUTHOR]

An extreme rainstorm can cause thousands of landslides and kill hundreds of people. In the changing climate, fatal rainstorms become more frequent and intense. The current landslide emergency management evaluates hazard intensities but lacks key information on likely consequences. This study presents a novel prompt quantitative risk assessment method for rain-induced landslides. The proposed method automatically generates a one-page risk assessment report within minutes to support effective risk communication, resource allocation, and emergency response. The propagation of uncertainties is quantified in a scientific probabilistic framework. The proposed method is tested using 83 major rainstorms during 1995–2016 in Hong Kong. The method accurately predicts the number of affected buildings and the number of potential fatalities and identifies rainstorms that can trigger fatal landslides. The proposed method contributes to the advancement of landslide emergency management from hazard-informed to risk-informed, which will significantly enhance societal resilience and facilitate climate change adaptation. [ABSTRACT FROM AUTHOR]

The spatiotemporal distributions and physical–optical properties of aerosols are of great scientific significance for the study of climate change and atmospheric environment. What are the characteristics of aerosols in constant high humidity? Continuous wet weather (CWW) is a special weather phenomenon that occurs frequently during the late winter and early spring in South China. In this study, the CALIPSO satellite data and the ERA5 and MERRA-2 reanalysis data are used to analyze the aerosol optical properties of a total of 68 CWW processes from 2012 to 2021 in the Guangdong–Hong Kong–Macau Greater Bay Area (GBA). We attempt to explore the variations in meteorological conditions and physical–optical properties of aerosols during the before-stage, wet-stage, and after-stage under different humidity levels. The results show that the prevailing wind direction is northeasterly and that the temperature and humidity are lower under the influence of cold high pressure in the before-stage. Moreover, the high aerosol optical depth (AOD) mainly results from regional transport. During the wet-stage, clean ocean airflow causes AOD to remain at a low level, whereas temperature and humidity increase significantly. The wet-stage ends with coldness when it is controlled by cold high pressure again. The atmospheric circulation in the after-stage is similar to that in the before-stage. However, a remarkable feature is that there is a temperature and humidity inversion layer, which results in a significant increase in AOD. This study reveals the physical–optical properties of aerosols during the three stages and the influence mechanism of meteorological factors on aerosols, which can provide a scientific basis for the study of CWW in the future. [ABSTRACT FROM AUTHOR]

• A multi-model and multi-method ensemble approach for wind resource projection is proposed. • Future wind potential in Hong Kong is assessed for the first time. • Robustness of the climate change signal is evaluated. • An increase in wind power density during summer (+23.7 %) and a decrease during autumn (–15.1 %) in 2081–2100 are projected for SSP5-8.5. Harvesting renewable wind energy is among the most cost-efficient means of reducing carbon emissions and achieving carbon neutrality. However, wind resource is susceptible to climate change impacts since the global temperature increase will reshape atmospheric circulation patterns. To facilitate the evaluation of fine-scale wind energy potential under climate variability, this paper proposes and validates a multi-model and multi-method ensemble wind resource projection approach. Then this approach is utilized to investigate the future variation of wind resources in Hong Kong based on the combined use of global climate models from Coupled Model Intercomparison Project Phase 6 and long-term observations from meteorological stations. It is found that there is a significant increase in future wind resources during summer, while a remarkable decline is projected during autumn. Nevertheless, the variations of wind resources in winter and spring are relatively insignificant. The outcomes of this study are expected to offer a framework for fine-scale wind resource assessment under climate change, and facilitate the economic and risk assessments of future wind farm projects. [ABSTRACT FROM AUTHOR]

This work offers a new perspective on the predictions of the wind fields of typhoons in Hong Kong, which takes into consideration the effects of climate change. An integrated model combining (1) the Monte-Carlo simulation methodology, (2) four future climate change scenarios gathered from the shared socioeconomic pathways (SSPs), and (3) a refined typhoon wind field model combined with the probabilistic models of typhoon key parameters has been developed and validated herein, by employing the four climate scenarios reported in Phase 6 of the Coupled Model Intercomparison Project. The direct consequence is that the probability distributions of the six key parameters of a typhoon's wind fields—translational velocity, approach angle, central pressure deficit, the radius of maximum wind, the distance of closest approach, and annual occurrence rate—should be modified according to the increase in sea surface temperatures. In this study, the key parameters are drawn from the modified distributions and input into the refined wind field models to predict the typhoon wind field in the future with preset climate change scenarios. Via the Monte-Carlo simulations of 10,000 virtual typhoons, the probabilistic characteristics of the typhoon wind speeds and directions are predicted. More specifically, the predictions at the Waglan Island in Hong Kong are compared with the corresponding statistics calculated from the current meteorology database, and the comparisons suggest that the rise of SST will result in slight increases in typhoon wind speeds. In addition, the typhoon wind direction, in general, drifts counterclockwise due to the increase in SSTs. [ABSTRACT FROM AUTHOR]

Possible thermodynamic effects of global warming on the landfalling typhoons that affect South China and their associated storm surges over Pearl River Delta region are investigated, using the Weather Research and Forecasting (WRF) Model and the Sea, Lake, and Overland Surges from Hurricanes (SLOSH) model based on the pseudo–global warming (PGW) technique. Twenty intense historical TCs that brought extreme storm surges to Hong Kong since the 1960s are selected and replicated by the 3-km WRF Model, with the outputs to drive the SLOSH model in storm surge simulation. The tracks, intensities, storm structure, and induced storm surges are well simulated. The PGW technique is then used to build a warmer background climate for the 20 selected TCs in the period of 2075–99 under the RCP8.5 scenario. To obtain a better adjusted warming environment, a pre-PGW adjustment method is developed. Comparing the same TCs in PGW experiments and historical runs, the TC lifetime peak (landfall) intensity can be intensified by about 9% 6 8% (12% 6 13%), with a ∼3% increase of TC peak intensity per degree of SST warming being inferred. The TCs are projected to be more compact, with the radius of maximum wind (RMW) reduced by ∼7% 6 10%. TC precipitation is also expected to increase, with the extreme precipitation within the eyewall strengthened by 22% 6 12%. All the above characters have passed the Student’s t test at 0.05 significance level. Finally, the projected induced storm surges near the Hong Kong waters are not significantly tested, although a weak storm surge height increase tendency is revealed. [ABSTRACT FROM AUTHOR]

Urban resilience is an attractive concept among academies and governments with the increasing severity of climate change and relevant disasters in cities. Few studies have been conducted to compare the key elements of attentions for enhancing urban resilience among Asian cities, although resilience is context-dependent. This study aims to compare the key elements of attentions for enhancing urban resilience among Singapore, Hong Kong and Hangzhou. A comprehensive literature review and expert interview validation were used to solicit the preliminary elements of attentions for enhancing urban resilience. Planners and researchers in the field of urban planning were surveyed to assess the significance level of the preliminary elements in the three case cities, as professional knowledge is required in the survey. Statistics were used to identify the key elements of attentions in the three case cities. Results demonstrate that the three cities have various elements of attentions for enhancing urban resilience despite sharing many similarities, which also demonstrate the guidance limitation of the general urban resilience framework. It also provides a reference for other international comparisons. [ABSTRACT FROM AUTHOR]

Urban heat island (UHI) and cool island (UCI) effects are well‐known and prevalent in cities worldwide. An increasing trend of extreme heat events has been observed over the last few decades and is expected to continue in the foreseeable future. In this study, warm periods (May to September) of 2000–2018 were examined to acquire a comprehensive understanding of the UHI and UCI characteristics for the case study of Hong Kong, China. Twenty‐two weather stations in Hong Kong were classified into four categories, namely urban, urban oasis, suburban, and rural, with reference to the local climate zone (LCZ) scheme, to analyze UHI and UCI phenomena during extreme heat and non‐extreme heat situations. One representative type of extreme heat events was considered in this study: three consecutive hot nights with two very hot days in between (2D3N). Results show that both the UHI and UCI effects are exacerbated during extreme heat events. Using the concept of the UHI degree hours (UHIdh) and UCI degree hours (UCIdh), their spatial patterns in Hong Kong during extreme heat and non‐extreme heat situations were mapped based on multiple linear regression models. It is found that the predictor variable – windward/leeward index is a significant influential factor of both UHIdh and UCIdh during extreme heat events. The resulting UHIdh and UCIdh maps not only enhance our understanding on the spatial pattern and characteristics of the UHI and UCI during extreme heat events, but could also serve as a useful reference in climate change adaptation, heat‐health risk detection, cooling‐energy estimation and policy making. [ABSTRACT FROM AUTHOR]