Climate Change and Viticulture in Italy: Historical Trends and Future Scenarios

(1) Background: The aim of this work was to characterize climatic evolution and change based on multicriteria classification through the dynamics of bioclimatic indices in viticulture across Italy and its regional administrative boundaries, focusing on latitudes and elevations. (2) Methods: This study analyzes climate change influences on Italian viticulture with reference to historical information (1991–2021) and future scenarios (until 2080) primarily based on the SSP2-4.5 and SSP5-8.5 scenarios, taking into account 13 GCMs. (3) Results: The bioclimatic indices have all shown a significant trend in the historical period, with an increase in temperature and a decrease in precipitation, reflecting their effects on the entire Italian territory with respect to the HI, up to 44° N for the CI, and up to 46° N for the DI, regardless of altitude. The future scenarios highlighted a shift towards the warmer classes of the two temperature-based indices (HI and CI) for both SSPs, especially for altitudes up to 900 m a.s.l. The DI-based classification based on the DI remained relatively stable in Italy over time, although DI values will become increasingly negative in the near future. (4) Conclusions: The climate in Italy is warming, especially in the south and in the coastal regions. By 2080, more areas will be “very hot” with “warm nights”. Drought will also increase and have a negative impact on viticulture. These findings spotlight the need for adaptive strategies in viticulture to hold satisfactory productivity under changing climatic conditions.