Contains functions for retrieving, managing and analysing air quality and weather data from Regione Lombardia open database (< https://www.dati.lombardia.it/>). Data are collected by ARPA Lombardia (Lombardia Environmental Protection Agency), Italy, through its ground monitoring network. See the webpage < https://www.arpalombardia.it/Pages/ARPA_Home_Page.aspx> for further information on ARPA Lombardia's activities and history. Data quality (e.g. missing values, exported values, graphical mapping) has been checked involving members of the ARPA Lombardia's office for air quality control. The package makes available observations since 2011 and are updated with daily frequency by the regional agency.