Analysis of the long-time climate data series for Turin and assessment of the city's urban heat island

In this article, we study the historical temperature and precipitation series for Turin and investigate the origins and effects of the city's urban heat island. The data under study are part of some of the longest meteorological data series for the whole of Italy. The findings detailed here are the result of historical research and the retrieval of data regarding climate parameters and associated metadata. We performed quality control assessments and used a homogenisation process to remove possible errors which may have occurred in the recording of the data. We also analysed changes and trends in climate and climatic index data for a 147-year period (1870-2016), and compared thermometric data from four rural stations with the Turin series to evaluate the urban heat island effect. Finally, we assessed a number of empirical models based on the number of inhabitants, the extent of urban growth and the increase in private and public transport usage in Turin to identify the urban heat island's evolution.