This study presents a valuable long-term analysis of the relationship between dry springs and hot European summers. It combines documentary evidence, the 600-year ModE-RA reconstruction, and complementary model simulations and reanalyses. One of its particular strengths is the consistency of the identified relationship across different datasets and approaches. Southeastern Europe emerges as a key region where spring precipitation deficits are associated with subsequent summer warming and more intense heat waves. A detailed analysis of historical extremes, including the exceptional summer of 1473, illustrates the atmospheric and hydroclimatic processes involved. Notably, the regression analysis reveals that late-spring precipitation, especially in April and May, influences summer temperatures independently of atmospheric circulation. Overall, the manuscript offers a useful historical perspective on compound heat-drought hazards and provides relevant insights for understanding past climate extremes and present-day European climate risks.