We studied the apparent time change of dialect areas on the basis of data of 86 local dialects of Dutch and Frisian that we collected in the period 2008-2011. In each location, recordings were made of two older male speakers and two younger female speakers. Using the transcriptions, we calculated linguistic distances among the speakers and classified the 172 speakers in natural groups by using bootstrap clustering. We used Ward’s clustering, which minimizes the total within-cluster variance. Comparing the groupings of the older male speakers with those of the younger female speakers we found that the number of groups decreased and the size of the Hollandic group increased at the lexical and morphological level. We also weighed words by their frequency of use. For the weighed data we found a smaller number of groups and a significantly larger Hollandic area at the morphological level than for the unweighed data. This may indicate a new ‘Hollandic expansion’.