Urban parks reduce the temperature and increase the relative humidity in the municipality of Santo André
Urban areas are shelter for a great percentage of human population, but the expansion of these areas generates changes in microclimate. These changes are usually associated to the occurrence of heat islands, increasing temperature and reducing the humidity. The protection of native vegetation and the creation of parks, squares, gardens and other green areas are considered important management actions to reduce heat island effect and improve the provision of multiple ecosystem services in urban areas. However, in most cities of developing countries, public managers usually do not invest in the creation of green areas, and their effects on the surrounding areas are not evaluated. In this context we evaluated the influence of urban parks on the air temperature and relative humidity of their surrounding areas. We evaluated the effect of 11 urban parks in Santo André municipality by measuring the temperature and relative humidity along transects starting from the park edges. We adopted a linear mixed model approach to evaluate the average influence of all the parks and also to estimate the average effect of each park. Our results revealed a significant effect of parks in reducing the temperature and increasing the air humidity. We detected a mean increase of 0.22 °C and a reduction of 0.7% of relative humidity after 100 m from the parks. When we analyzed the 11 parks individually, we found significant influence of the parks on the temperature and humidity for 7 and 9 parks, respectively. Our results showed the relevance of the urban parks in reducing the temperature and increasing air humidity in Santo André. However, in some regions the presence of parks must be complemented by new green areas and street trees to counterbalance the negative effects of urban geometry and improve benefits of green areas.