A first assessment of the main climatic drivers that modulate the tree-ring width (RW) and maximum latewood density (MXD) along the Italian Peninsula and northeastern Sicily was performed using 27 forest sites, which include conifers (RW and MXD) and broadleaves (only RW). Tree-ring data were compared using the correlation analysis of the monthly and seasonal variables of temperature, precipitation and standardized precipitation index (SPI, used to characterize meteorological droughts) against each species-specific site chronology and against the highly sensitive to climate (HSTC) chronologies (based on selected indexed individual series). We find that climate signals in conifer MXD are stronger and more stable over time than those in conifer and broadleaf RW. In particular, conifer MXD variability is directly influenced by the late summer (August, September) temperature and is inversely influenced by the summer precipitation and droughts (SPI at a timescale of 3 months). Conifer RW is influenced by the temperature and drought of the previous summer, whereas broadleaf RW is more influenced by summer precipitation and drought of the current growing season. The reconstruction of the late summer temperatures for the Italian Peninsula for the past 300 yr, based on the HSTC chronology of conifer MXD, shows a stable model performance that underlines periods of climatic worsening around 1699, 1740, 1814, 1909, 1939 CE and well follows the variability of the instrumental record. Considering a 20 yr low-pass filtered series, the reconstructed temperature record consistently deviates < 1 °C from the instrumental record. This divergence may be due also to the precipitation patterns and drought stresses that influence the tree-ring MXD at our study sites. The reconstructed temperature variability is valid for the west-east oriented region including Sardinia, Sicily and the western Balkan area along the Adriatic coast.