The role of clouds in daytime thermal comfort in Itapecerica da Serra, Brazil

Abstract

The advancement of human occupation in urban centers associated with inadequate planning of cities, over the years has resulted in various environmental and climatic problems, resulting in a challenge for the quality of life of populations. The central problem of this study consists of investigating the relationship between the elements cloudiness and thermal comfort in their diurnal variation in the city of Itapecerica da Serra/SP. The methodological procedures developed were: photographic recording of the sky, collection of air temperature and relative humidity data and thermal comfort calculated with the Missenard resultant temperature index (ITR). Data were collected at three different points in the city at times (9 am, 1 pm and 5 pm), and with representative episodes in three periods of the year, (November 2020, February and July 2021). The results indicate a trend towards greater cloudiness in the months of November 2020 and February 2021. Regarding thermal comfort, it was possible to observe greater discomfort due to cold in the month of July (2021), mostly in the morning (9 hours). Heat discomfort was notable in February 2021 in the early afternoon (1 pm). The relationship between both elements indicated that the presence of clouds interferes with thermal comfort. In maximum situations of heat discomfort there is the presence of clouds in the sky, especially low clouds. The maximum situations of discomfort due to cold were associated with days with open skies or high clouds.