This article reports ongoing investigations into phonetic change of dialect groups in the northern Netherlandic language area, particularly the Frisian and Low Saxon dialect groups, which are known to differ in vitality. To achieve this, we combine existing phonetically transcribed corpora with dialectometric approaches that allow us to 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 phonetic distances between transcriptions, is used to estimate how much dialect groups have changed between 1990 and 2010, and whether they changed towards Standard Dutch or away from it. Our analyses indicate that language change is a slow process in this geographical area. Moreover, the Frisian and Groningen dialect groups seem to be most stable, while the other Low Saxon varieties (excluding the Groningen dialect group) were shown to be most prone to change. We offer possible explanations for our findings, while we discuss shortcomings of the data and approach in detail, as well as desiderata for future research.