Abstract. A data set of annual freshwater ice phenology was compiled for the largest river (Danube) and the largest lake (Lake Balaton) in East Central Europe, extending regular river and lake ice monitoring data through the use of historical observations and documentary records dating back to 1774 AD and 1885 AD, respectively. What becomes clear is that the dates of the first appearance of ice and freeze-up have shifted, arriving 12–30 and 4–13 days later respectively per 100 years. Break-up and ice-off have shifted to earlier dates by 7–13 and 9–27 days/100 years, except on Lake Balaton, where the date of break-up has not changed significantly. The data sets represent a great potential resource for (paleo)climatological research thanks to the strong, physically determined link between water and air temperature and the occurrence of freshwater ice phenomena. The derived centennial records of freshwater cryophenology for Danube and Balaton are readily available for detailed analysis of the temporal trends, large-scale spatial comparison or other climatological purposes. The derived dataset is publicly available via PANGAEA at https://doi.org/10.1594/PANGAEA.881056.