Aims: The continuous rise in air temperature driven by rapid urbanization and ongoing climate change has become one of the most critical environmental challenges of the twenty-first century, particularly in hot and humid coastal cities. In these environments, elevated temperatures combined with high humidity intensify thermal stress and severely diminish outdoor thermal comfort at the neighborhood scale. Although a substantial body of literature has examined urban heat islands (UHIs), the majority of existing studies have concentrated on metropolitan or city-wide scales. Consequently, the precise identification of thermally critical zones—localized urban heat islands—at the finer neighborhood scale, and the systematic examination of their relationship with the physical and morphological characteristics of urban textures, have received comparatively limited attention. This research gap is especially pronounced in coastal urban settings where natural ventilation regimes and microclimatic conditions are strongly influenced by proximity to the sea and by the configuration of the built environment. Determining which parts of a neighborhood are most vulnerable to climate-induced thermal stress and to reductions in natural ventilation is therefore essential. Such knowledge can serve as a robust scientific foundation for prioritizing climate-responsive interventions in urban design and planning, enabling decision-makers to allocate limited resources more effectively toward the enhancement of thermal comfort and the strengthening of climate resilience in coastal fabrics.
Materials & Methods: The present study was designed and conducted with the explicit objective of identifying thermally critical areas within two contrasting coastal urban contexts of Bandar Abbas city: a traditional (native) neighborhood fabric and a more recent, planned (developed) fabric. Field measurements of air temperature and wind speed were carried out at carefully selected monitoring stations distributed throughout both neighborhoods. Data collection was performed systematically to ensure spatial representativeness and temporal consistency. To analyze the thermal behavior of the two fabrics, a combination of spatial trend analysis techniques was employed. The nonparametric Mann–Kendall test was applied to assess the statistical significance of temporal trends in the measured variables, while the Sen’s slope estimator was used to quantify the magnitude and direction of these trends. In addition, threshold analysis was performed to detect points of abrupt change in the behavior of air temperature and wind speed. These change points were interpreted as indicators of the onset of thermally critical conditions. Within the conceptual framework of this research, a thermally critical area is defined as a portion of the neighborhood in which a measurable decline in natural ventilation coincides with a noticeable rise in air temperature, causing local thermal conditions to approach or exceed the upper limits of the human thermal comfort range. This integrated methodological approach allowed for a spatially explicit and statistically rigorous delineation of critical zones.
Findings: The analytical results revealed a statistically significant decreasing trend in wind speed across both the native and developed fabrics, confirming a progressive weakening of natural ventilation in the studied coastal neighborhoods. Despite this shared decline in airflow, the thermal responses of the two fabrics differed markedly. The native texture, characterized by its compact morphology, narrower pathways, and traditional spatial organization, demonstrated greater thermal stability in the face of reduced ventilation; the temporal trend of air-temperature change within this fabric was not statistically significant. In contrast, the developed fabric exhibited heightened sensitivity to the reduction in air movement, displaying a clear positive slope in temperature trends. Thermally critical areas emerged predominantly in the terminal or peripheral sections of the neighborhoods, coinciding spatially and temporally with the most pronounced decreases in wind speed. These findings underscore the differentiated capacity of traditional versus contemporary urban forms to buffer against microclimatic deterioration under conditions of diminishing natural ventilation.
Conclusion: Collectively, the research findings demonstrate that the pattern of natural ventilation and the physical-morphological organization of neighborhoods play decisive roles in the formation and spatial distribution of thermally critical areas. The greater resilience observed in the native fabric highlights the microclimatic advantages inherent in traditional coastal urban patterns, while the heightened vulnerability of the developed fabric points to the need for more careful climatic consideration in contemporary urban design. The methodological approach developed for identifying thermally critical zones offers an efficient and transferable tool for locating priority areas that require climate-oriented interventions. By enabling the precise spatial targeting of design measures, this approach can facilitate the formulation of practical, climate-responsive strategies aimed at improving outdoor thermal comfort and enhancing the overall climate resilience of coastal urban textures. Future applications of the method in other hot-humid coastal cities may further refine its utility and contribute to the development of evidence-based guidelines for sustainable urban planning under conditions of accelerating climate change.