This article reports investigations into sound change at the community-level of Frisian and Low Saxon dialect groups in the north of the Netherlands, which differ in key factors influencing dialect decline. We combine phonetically transcribed corpora with dialectometric approaches that can quantify change among older male dialect speakers in a real-time framework. A multidimensional variant of the Levenshtein distance, combined with methods that induce realistic distances between sounds, is used to estimate how much dialect groups converged to and diverged from Standard Dutch between 1990 and 2010. Our analyses indicate that sound change is a slow process in this geographical area. The Frisian and North Low Saxon dialect groups seem to be most stable, while Westphalian Low Saxon varieties seem to be most prone to change. We offer possible explanations for our findings and discuss shortcomings of the data and approach in detail.