Abstract An important assumption underlying most if not all methods of dialectometry is that the automated analysis of the differences in language use between different locations, as they are recorded by dialectologists in large scale surveys, can reveal patterns which directly reflect regional variation. Focusing on lexical variation, this chapter examines the role of concept characteristics in lexical dialectometry in three consecutive logical steps. First, it conducts a regression analysis of data taken from a large lexical database of Limburgish dialects in Belgium and the Netherlands to show that concept characteristics such as concept salience, concept vagueness and negative affect contribute to the lexical heterogeneity in the dialect data. Next, it demonstrates that the relationship between concept characteristics and lexical heterogeneity influences the results of conventional lexical dialectometric measurements. Finally, the chapter proposes a lexical dialectometric method in which concept characteristics form the basis of a weighting schema that determines to which extent concept specific dissimilarities can contribute to the aggregate dissimilarities between locations.