Climate Diversity of Urban Parks: Exploring the Influence of Size, Composition, and Greenery Features

Rising air temperatures and prolonged hot spells are increasing the role of urban vegetation. Urban parks and all nature-based solutions introduced in cities play a huge role in climate change adaptation. In Warsaw (Poland), urban greenery (parks, river valleys, and allotment gardens) accounts for 15.5% of the area, and forests account for another 15%. However, the city planned to reduce this area by 5% by 2050. The average intensity of the urban heat island in urban greenery is 0.6°C, compared to 2.6°C within intensive inner city development or 2.8°C near major transport arteries. This confirms the great role of greenery in shaping urban climate and bioclimate.

The results of the CLIMPARK project examining the climate of 6 parks in Warsaw with areas ranging from 3.5 ha to 78 ha indicate that during summer, the air temperature on the permanent meteorological stations located in open spaces in the parks is, on average, 1.0°C-1.5°C lower compared to the built-up area. However, the 10-minute differences between these locations reach 6.5°C, while the differences between shaded parts of the park and the built-up area exceed 8°C. During the cold half of the year, average differences are smaller and amount to 0.6-0.8°C.

The thermal differences within the park can also be significant depending on its size, the structure of the vegetation, and the site itself. Average differences between shaded and sunny areas recorded in the park in the summer exceed 3°C, and the differences in 10-minute values reach 5°C. The project attempts to develop a model of the intensity of the air cooling effect depending on the park's features. The impact of parks on reducing the exposure to heat stress of people living in their vicinity will also be estimated.