Do Precipitation and Temperature Influence Perceptions of Urban Cleanliness?

This study explores the correlation between weather and the perception of urban cleanliness across the 47 largest cities in Spain. Utilizing survey data conducted by the national Consumers and Users Organization (OCU) in 2015, 2019, and 2023 to assess cleanliness perceptions, we analyze potential associations with precipitation and temperature recorded by weather stations of the Spanish Meteorological Agency. Additionally, we consider computed values of the De Martonne aridity index. The OCU data reveal regional disparities in perceived cleanliness quality. Higher cleanliness scores are obtained in cities located in the northern and north-central regions of Spain, characterized by humid and super-humid climates according to the De Martonne index. Conversely, lower cleanliness ratings are given to cities in the southern and eastern regions of Spain, where a Mediterranean climate and lower aridity index values prevail. In conducting a statistical analysis on the perception of cleanliness and variables related to precipitation and temperature, the results of the chi-square and linear correlation tests found no strong statistical correlation, although a tendency is observed. Cities with higher annual precipitation and lower values of average annual temperature tend to receive better cleanliness ratings, while drier and warmer cities exhibit the worst values of perceived urban cleanliness. Furthermore, our findings indicate that the Gompertz model effectively captures a strong statistical correlation in the relationship between cleanliness perception and the De Martonne index: As aridity increases, cleanliness perception decreases. These results are relevant for the development of future cleaning methods and systems, particularly in light of the climate change scenarios that are anticipated in the Mediterranean region due to warmer and drier conditions and, consequently, an increase in aridity.