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While outdoor thermal comfort (OTC) research in cold climate cities is expanding, comprehensive studies quantifying the seasonal impacts of urban morphology remain limited. This study fills a critical gap by establishing season-specific neutral Physiological Equivalent Temperature (PET) thresholds in Shenyang (Dwa climate, Northeast China) through 1,009 paired microclimate measurements and subjective surveys. Results show markedly lower thermal neutral points—12.5 °C in winter and 22.5 °C in summer—reflecting distinct cold-adaptive behaviors. This study provides empirical evidence quantifying the seasonal influences of urban morphology on OTC in a severe cold zone. The proposed Sky View Factor (SVF)-sensitive comfort framework advances climate-responsive design, providing empirical thresholds and parametric tools for cold-region planning. Findings contribute new evidence supporting seasonal adaptation theory and empirically offer a transferable methodology for similar high-latitude cities globally.

In hot climate regions, the direct impact of solar radiation on building surfaces, including heat absorption and storage, negatively impacts outdoor comfort and the living conditions of urban residents. This study investigates the impact of urban street geometry on building surface temperatures in a hot and dry climate, focusing on the traditional Suriçi district of Diyarbakır. Measurements were conducted at 25 locations throughout the year along streets with varying sky view factor (SVF) values and within vaulted covered passages (kabaltıs). In the study, a Testo 410-2 anemometer was used to measure air temperature and a thermal camera was used to measure surface temperature. The results show smaller daily surface temperature amplitudes in regions with lower SVF values and in kabaltıs with an SVF value of 0. Measured surface temperatures reached as high as 58.8 °C at high SVF locations, while they remained around 30 °C in shaded kabaltıs. The findings indicate that street geometry parameters such as building height, spacing, and orientation significantly influence microclimate conditions. Differences of up to 15–20 °C were observed between shaded kabaltıs surface temperatures and other surface temperatures at measurement points where the SVF value was close to 1. Reducing SVF through design strategies such as the use of kabaltıs and planting trees can improve outdoor thermal comfort in hot climates.

With the increase in population in cities, economic, social, and environmental problems continue to increase, and it is thought that the microclimatic conditions created by these problems will cause more environmental problems. One of the factors affecting the urban climate in urban areas is urban geometry. The climate of a region changes due to the shape of the land surface, human activities, atmospheric movements, and latent and sensible heat fluxes. Sky view factor (SVF), building view factor (BVF), and tree view factor (TVF) are actively used in the determination of urban geometry. However, studies on how these factors affect the thermal state of the urban environment are insufficient. Determining the land surface changes and thermal condition characteristics (LST, NDVI, SHF, and LHF) depending on urban growth and examining how these properties affect thermal conditions are very important in the construction of sustainable urban planning. In the study, SVF, BVF, TVF, LST, NDVI, SHF, and LHF values of 55 points determined for three different areas with different urban geometries were calculated. How these values affect each other and their situation on urban outdoor thermal comfort is evaluated. In the study, statistical analysis was performed to evaluate the relationship between surface temperature, surface heat fluxes, different view factors, and vegetation. As a result of ANOVA analysis, it was determined as very significant ( p  > 0.01) in all regions. Both SHF and LHF values differ with SVF. The SHF value has a direct relationship with the SVF value. LHF is inversely proportional to the SVF value. The situation is reversed for SHF variation concerning vegetation. LHF and NDVI are directly related. SHF and NDVI are inversely proportional. SVF and NDVI values also vary according to the LST value. It has been observed that LST has a direct relationship with SVF and an inverse relationship with NDVI.

As China’s urbanization progresses, the urban heat island (UHI) effect has become more pronounced, impacting the health of residents and the activity intentions of visitors within historic urban areas. This study focuses on the historic district of the Three Lanes and Seven Alleys Tourist Area (SFQX) in Fuzhou, where simulations were conducted on four representative streets across various times during a typical summer meteorological day. Typological methods were employed to simplify neighborhood modeling, and Phoenics software was utilized to simulate the neighborhood’s wind environment and the outdoor pedestrian thermal comfort index. Aspect ratio (AR), sky view factor (SVF), air velocity (Va), and universal thermal climate index (UTCI) values at specific locations were collected for statistical analysis. The findings reveal that: (1) the N–S orientation exhibits more significant correlations between Va, the UTCI, and street geometry compared to the E–W orientation; (2) the relationship between SVF and the UTCI fluctuates with time; (3) areas with higher AR values, such as medium and deep canyons, offer better thermal comfort for outdoor pedestrians; and (4) at 8:00, the UTCI and wind speed show minimal correlations with street geometry and direction, being predominantly influenced by objective climatic factors. These insights are expected to significantly inform the geometric design and planning of streets in Fuzhou’s historic districts, aiming to create more comfortable outdoor environments for inhabitants and visitors alike.

With non-rainfall water (NRW), principally dew and fog, serving as an important water source, especially in arid and semiarid regions, factors that may increase the NRW yield may have important hydrological and ecological consequences. On the other hand, dew and fog may also have hazardous effect on inorganic and human-made materials that may undergo corrosion and/or degradation. It has long been noted that dew and fog are affected by neighboring objects, the effect of which was, however, only barely explored. Hypothesizing that it may principally be linked to the sky view factor (SVF) (determining, in turn, substrate temperature and heat flow) and, therefore, to the angle that is formed between the collecting substrate and the height of the neighboring objects, a set of square boxes (30 × 30 or 60 × 60 cm) was constructed. The boxes had variable heights, forming angles of 15°, 30°, 45°, 60°, and 75° between 6 × 6 × 0.1 cm cloth attached to a substratum (10 × 10 × 0.2 cm glass plate overlying 10 × 10 × 0.5 cm plywood) at the center of each box and the top walls of the box. NRW that accumulated at the cloths was compared with cloths placed in the open, serving as control. Another set served to measure the plate temperatures. A clear decrease in NRW, with an angle corresponding to a third-degree polynomial equation, was found (r2 = 0.998). Taking 0.1 mm as the threshold for vapor condensation (dew), and taking the average maximal NRW as measured for two years in the Negev (0.20 mm), angles of ≥45° will suffice to impair condensation. However, with the projected decrease in NRW with global warming, even angles of ≥30° may impair condensation in 1–2 decades. While it may decrease the dew amounts and subsequently negatively affect the vegetation in forest clearings and wadis or canyons, it may decrease the exposure of construction materials to corrosion and/or degradation, thus exerting a positive effect on construction materials in urban settings.

University campuses feature spatially diverse environments where thermal performance varies seasonally and spatially. In this study, we integrate field measurements with ENVI-met simulations to evaluate how sky view factor (SVF) influences microclimate and outdoor thermal comfort-quantified via air temperature (Ta), mean radiant temperature (Tmrt), wind speed (WS), relative humidity (RH), physiologically equivalent temperature (PET), and the Universal Thermal Climate Index (UTCI)-within urban street and urban building spaces on a temperate Chinese campus. The results reveal contrasting thermal responses: in summer, low-SVF urban street spaces (SVF_avg 0.075) exhibit moderate heat stress (PET_avg 34.5–39.5 °C) due to radiative trapping and limited ventilation, whereas high-SVF urban building spaces (SVF_avg 0.159) face greater heat load and stronger thermal stress, with peak PET exceeding 49.9 °C. In winter, high-SVF urban building spaces benefit from solar gain, improving thermal comfort. Statistical analyses indicate non-linear threshold effects of SVF on comfort indices, with summer comfort positively correlated at SVF > 0.2, and winter comfort negatively associated at SVF ≤ 0.4. These findings identify SVF as a key geometric predictor of seasonal thermal comfort in distinct campus spatial types, provide quantitative thresholds to guide climate-resilient campus planning in warm temperate zone.

Hong Kong is a typical high-density city in a subtropical climate region, and deep street canyons are among the main features of its urban planning. How the urban geometry influences the urban thermal environment in this city has become a hot topic these days. The height-to-width ratio (H/W) and sky view factor (SVF) are commonly used to indicate the outdoor thermal environment performance, while previous studies in Hong Kong rarely analysed the importance bias of these two influencing factors systematically in this context. To fill this research gap, in this paper, we chose four typical sites in Hong Kong as research objects. Firstly, we conducted a field investigation to calculate the main influencing factors of urban street geometry (H/W and SVF) and then used field measurements to collect climatic data, including air temperature, wind speed, and relative humidity, and finally used regression to analyse the correlation between H/W, SVF, and temperature. The results indicate the following: (1) There is a greater correlation between H/W and air temperature than between SVF and air temperature by regression analysis, and H/W is more effective at improving the thermal environment within urban street canyons. (2) After field measurements, it was found that H/W at the measurement sites was 0.60 to 6.02, with an average of 2.13. (3) In the study area, H/W of 2.31–2.48 and 3.35–3.60 had a positive correlation with air temperature, and H/W had a dominant influence on outdoor air temperature, and H/W of 2.09–2.31 and H/W > 3.60 was inversely related to air temperature. The conclusions can provide support for urban planning in Hong Kong.

In the context of urbanization, research on urban microclimate and thermal comfort has become one of the themes of eco-city design. Sky view factor (SVF), one of the parameters of urban spatial form, combines multiple morphological information, such as plane opening, aspect ratio, and building density and has an important impact on the urban microclimate. However, there is still no clear research conclusion on the correlation between SVF and microclimate. In this paper, nine Local Climate Zone (LCZ) models are used and typical summer meteorological conditions of Nanjing are applied as an attempt to partially fill this gap. The calculated microclimate and thermal comfort indices include air temperature (AT), surface temperature (ST), relative humidity (RH), wind speed (WS), mean radiant temperature (MRT), and predicted mean vote (PMV). Results show that the local effect of urban morphology on thermal comfort can be retrieved from the use of comprehensive parameters such as SVF (which takes into account the building height, layout, and density) whose distribution in the investigated models showed to be correlated with MRT, so did PMV under low wind speed conditions.

This study explores the impact of microclimatic variations on thermal perception and walking experience in Béjaïa, Algeria, focusing on two contrasting urban areas: the compact historic medina and the modern lower city. A mixed-method approach combined microclimatic measurements (Ta, Ts, Va, RH) with subjective evaluations from 70 participants. After urban morphological analysis, walking itineraries were designed and studied through accompanied walks. Participants reported their thermal sensations and walking comfort via questionnaires and mental maps, while environmental data were simultaneously collected (21–28 July 2022). Results show that transitions between urban fabrics significantly affect thermal sensation and walking thermal comfort (WTC). Strong correlations were observed between surface temperature (Ts) and sky view factor (SVF), and between ASV and WTC (Kendall’s τᵦ = 0.79, 95% CI [0.70, 0.88]). Beyond physical factors, perceptual variables like vegetation (OR = 1.50), maintenance (OR = 1.40), and views (OR = 1.30) significantly increased WTC, while fatigue (OR = 0.70) and safety concerns (OR = 0.80) reduced it. The findings highlight strong contrasts between the two areas and support planning strategies emphasizing vegetation, spatial optimization, and the integration of perceptual thermal factors in urban design.

Previous studies have found that built-environment characteristics in large cities produce important effects of the urban heat island (UHI) and know the horizontal space affected by the urban canopy microclimate ranges from about 30–200 m, but there are few studies in medium-sized cities. Therefore, this study investigates canopy-scale built-environment characteristics and their correlation with urban heat island (UHI) effects in Chiayi city, a tropical, medium-sized city. Under a 100 m buffer size, 2D and 3D built-environment factors such as the green coverage ratio (GCR), building coverage ratio (BCR), floor area ratio (FAR), and sky view factor (SVF) were first analyzed and then correlated with the UHI effect. The analyses were repeated on 200 and 1000 m scales and compared to previous studies. It was found that the built-environment factors were more strongly correlated with UHI under the 200 m buffer. Moreover, 2D factors such as the GCR and BCR had a higher correlation with UHI, especially in developing medium-sized cities. Regarding the GCR, BCR, and FAR, as expected, the correlation coefficients with UHI increased to 0.4 at 13:00 during the day and changed from 0.2 to 0.4 at 00:30 at night, whereas the correlation between the SVF and UHI was greatly different from the study area or calculation methods. The scale effect and SVF calculation methods are recommended for further study.