During the last glacial period Northern Hemisphere climate was characterized by extreme and abrupt climate changes, so-called Dansgaard-Oeschger (DO) events. Most clearly observed as temperature changes in Greenland ice-core records, their climatic imprint was geographically widespread. However, the temporal relation between DO-events in Greenland and other regions is uncertain due to the chronological uncertainties of each archive, limiting our ability to test hypotheses of synchronous change. On the contrary, the assumption of direct synchrony of climate changes forms the basis of many timescales. Here, we use cosmogenic radionuclides ( 10 Be, 36 Cl, 14 C) to link Greenland ice-core records to U / Th-dated speleothems, quantify offsets between both timescales, and improve their absolute dating back to 45 000 years ago. This approach allows us to test the assumption that DO-events occurred synchronously between Greenland ice-core and tropical speleothem records at unprecedented precision. We find that the onset of DO-events occurs within synchronization uncertainties in all investigated records. Importantly, we demonstrate that there remain local discrepancies in the temporal development of rapid climate change for specific events and speleothems. These may be either related to the location of proxy records relative to the shifting atmospheric fronts or to underestimated U / Th-dating uncertainties. Our study thus highlights the potential for misleading interpretations of the Earth system when applying the common practice of climate wiggle-matching.