Urban green spaces can provide relaxation, exercise, social interaction, and many other benefits for their communities, towns, and cities. However, green spaces in hot and humid regions risk being underutilized by residents unless thermal environments are designed to be sufficiently comfortable. Understanding what conditions are needed for comfortable outdoor spaces, particularly how people feel in regard to their thermal environment, is vital in designing spaces for public use. Traditional gardens are excellent examples of successful microclimate design from which we can learn, as they are developed over the generations through observation and modification. This study analyzed how Japanese gardens affect people’s thermal stress on extremely hot summer days. Meteorological data was collected in three Japanese gardens, and human thermal comfort was evaluated through physiological equivalent temperature (PET). Statistical analysis examined the relationship between spatial configurations of the gardens and thermal comfort. Our study revealed that Japanese gardens can efficiently ameliorate thermal stress. Spatial analysis showed that garden elements affect thermal comfort variously depending on time of the day and spatial distribution.

Access to green space (GS) is vital for children’s health and development, including during daycare. In Japan, deregulation to alleviate daycare shortages has created a new category of so-called unlicensed daycare centers (UDCs) that often lack dedicated GS. UDCs rely on surrounding GS, including parks, temples and university grounds, but reports of conflicts highlight the precarity of children’s well-being in a rapidly aging country. Knowledge about GS access in Japanese UDCs remains scarce. Our mail-back survey (n = 173) of UDCs and online survey (n = 3645) of parents investigated threats to GS access during daycare across 14 Japanese cities. Results suggest that UDCs use a variety of GS and aim to provide daily access. Caregivers are vital in mediating children’s access, but locally available GS diversity, quality and quantity as well as institutional support were perceived as lacking. Parents did not rank GS high among their priorities when selecting daycare providers, and showed limited awareness of conflicts during GS visits. Implications of this study include the need for caregivers and parents to communicate and collaborate to improve GS access, and the importance of strong public investment into holistically improving GS diversity, quality and quantity from the perspective of public health and urban planning.

Small urban parks are the dominant form of green spaces in most Japanese cities and hold great potential for heat stress mitigation. However, most research has focused on large urban parks, leaving a knowledge gap in how small parks can be designed to mitigate heat. Given that small parks are primarily used for rest, we focused on resting areas and assessed their thermal conditions in three typical small parks in Kyoto, Japan. We then examined how the spatial arrangements of park elements influenced thermal conditions. Results revealed that nearly half of the resting areas were uncomfortable, underscoring the urgent need for spatial design improvements. Linear mixed-effects models showed that while shade elements, such as tree canopies and roofs, most effectively enhanced thermal perception, their effectiveness was distance- and orientation-dependent. We also found a critical mismatch between green ground and shade elements that adversely affected thermal conditions. Our findings highlight that strategic spatial design, particularly the thoughtful placement of shade elements and resting areas, is the key to providing thermal comfort in small urban parks. This study provides evidence that small parks can act as urban heat spots if poorly designed, but with appropriate design they can become cool refuges.

Tokyo, Japan, is one of the world’s most densely populated cities, with much of its land converted into impervious urban structures. Historically, the western part of the city was dominated by farmland and forests, some of which have persisted despite urban expansion. Many of the remnant forests are fragmented and isolated within the urban landscape yet continue to provide habitats for native species and deliver various ecosystem services. Recognizing their ecological value, the government has designated such areas as Tokyo Metropolitan Conservation Areas.This study focuses on the microclimate regulating service of the preserved forests, particularly those surrounded by residential areas. The aim is to assess their role in mitigating summer heat and benefiting residents, as well as to provide quantitative evidence of the service to enhance public recognition of the forests' ecological value, which remains underappreciated.We selected two preserved forests (~2.5 ha each) and conducted fixed-point and mobile temperature observations in September 2024. Fixed-point measurements were taken over one month within and surrounding the forests, while mobile observations were performed at noon and night over three days by cycling around the forests.Results show that, on sunny and calm days, forest temperatures averaged 0.75°C lower than surrounding areas. The difference was most pronounced at noon, with an average temperature difference of 2.1°C, while nighttime difference was negligible. Mobile observations revealed that at noon, the cool air within the forests remained largely confined, causing the pronounced temperature difference. At night, however, cooler temperatures were observed in the forests’ surroundings and temperatures increased gradually with distance, suggesting that the cool air had dispersed into the surrounding residential areas. In addition, other regulating services, such as air purification and flood regulating services, will also be discussed to provide a comprehensive understanding of the forests’ ecosystem services.