This study presents, for the first time, a detailed quantitative reconstruction of winter (January) and summer (July) palaeotemperatures from the Late Pleistocene to Holocene transition in central Italy based on ostracod assemblages in an 8.59-m-long sediment core retrieved in Lake Trasimeno. Of 19 ostracod species recovered, 13 were calibrated according to their living temperature ranges, enabling us to reconstruct mean January and July temperature ranges using the mutual ostracod temperature range (MOTR) method. The occurrences of Cytheromorpha fuscata and Limnocythere suessenbornensis from 44 000 to 25 500 cal. a BP showed mean January temperatures at least 7 °C colder and mean July temperature at least 1 °C cooler in some intervals compared to present-day temperatures. Comparison of the MOTR-derived January minima curve with a Greenland oxygen isotope record (NGRIP) shows a remarkable correlation of warmer Greenland Interstadial and the colder Greenland Stadial events with clear peaks and troughs in the MOTR signal. These correlations were tested successfully by tuning the MOTR curve to the NGRIP record, resulting in an improved age-depth model combining radiocarbon ages with MOTR tie points. The results demonstrate that a record of rapid climate change in the North Atlantic region is archived in lacustrine ostracod assemblages in central Italy.