The present work analyses the main weather patterns over the period 1981-2010 in the Central Apennines (Italy), drawing upon data from 23 monitoring stations spanning a wide elevation range (260-1750 m asl). Cluster analysis was used to identify homogeneous units and to verify the effectiveness of the bioclimatic classification by crossing the results derived from the application of hierarchical and non-hierarchical classification techniques. The results reveal a diversified picture of five clusters that depends on several factors as elevation, the geographic position within or outside the mountainous range, and the regional morphological traits. Although Mediterranean and Temperate climatic features coexist, the Mediterranean pattern in the southern areas and internal valleys better expresses the overall mixed characteristics of Central Italy. The use of a mixed methodology of hierarchic and partitioning methods of cluster analysis improves the bioclimatic classification, especially to quantify the level of humidity and the mediterraneity degree.
Keywords: Bioclimatic classification; Bioclimatic indices; Bioclimatology; Central Apennine; Climate change; Summer drought and sub-drought.