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Urban green space has been considered as an ecological measure to mitigate urban heat islands (UHI). However, few studies investigate the cooling effect of the adjacent area of the urban park; as the transition region from a green space to a hardened surface where more complex heat exchange occurs, it deserves to be paid more attention. This paper examines the relationship between the urban greening patterns and the cooling effect in the surrounding areas of the Olympic Forest Park in Beijing. Results showed that the forestland and waterbodies could cool 6.51% and 12.82% of the impervious surface temperatures, respectively. For every 10% increase in the green space ratio, the land surface temperature drops by 0.4°C, and per kilometer increase in the distance from the forest park, the land surface temperature increases by 0.15 °C. The aggregation index (AI) and largest patch index (LPI) of the green space patterns presented a strong negative correlation with surface temperature. This study confirms the cooling effects in the adjacent area of the urban park and highlights their dependence on urban greening patterns. Therefore, we should not only develop more green spaces but also scientifically plan their spatial configuration in the limited urban land for the improvement of the cooling effect.

The cooling effect of green spaces as an ecological solution to mitigate urban climate change is well documented. However, the factors influencing the microclimate in the built environment around forest parks, diurnal variations of their impact and their degree of importance have not been explicitly addressed. We attempted to quantify how much various landscape parameters, including land cover and spatial location, impact the ambient air and surface temperature in the area around Beijing’s Olympic Forest Park. Data were taken along strategically located traverses inside and outside the park. We found: (1) The air temperature during the day was 1.0–3.5 °C lower in the park than in the surrounding area; the surface temperature was 1.7–4.8 °C lower; air humidity in the park increased by 8.7–15.1%; and the human comfort index reduced to 1.8–6.9, all generating a more comfortable thermal environment in the park than in the surrounding area. (2) The distance to the park and the green space ratio of the park’s surrounding area are significant factors for regulating its microclimate. A 1 km increase in distance to the park caused the temperature to increase by 0.83 °C; when the green space ratio increased by 10%, the temperature dropped by 0.16 °C on average. The impact of these two parameters was more obvious in the afternoon than in the middle of the day or in the morning. The green space ratio could be used for designing a more stable thermal environment. (3) Land cover affects surface temperature more than it does air temperature. Our data suggest that an urban plan with an even distribution of green space would provide the greatest thermal comfort.

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