The calculation of aggregate linguistic distances can compensate for some of the drawbacks inherent to the isogloss bundling method used in traditional dialectology to identify dialect areas. Synchronic aggregate analysis can also point out differences with respect to a diachronically based classification of dialects. In this study the Levenshtein algorithm is applied for the first time to obtain an aggregate analysis of the linguistic distances among 88 diatopic varieties of Croatian spoken along the Eastern Adriatic coast and in the Italian province of Molise. We also measured lexical differences among these varieties, which are traditionally grouped into Čakavian, Štokavian, and transitional Čakavian-Štokavian varieties. The lexical and pronunciation distances are subsequently projected onto multidimensional cartographic representations. Both kinds of analyses confirm that linguistic discontinuity is characteristic of the whole region, and that discontinuities are more pronounced in the northern Adriatic area than in the south. We also show that the geographic lines are in many cases the most decisive factor contributing to linguistic cohesion, and that the internal heterogeneity within Čakavian is often greater than the differences between Čakavian and Štokavian varieties. This holds both for pronunciation and lexicon.