Introduction <p>Spain stands out as one of the countries most affected by rising heat-related mortality in Europe. The MoMo system is a daily all-cause mortality monitoring system that provides estimates of excess mortality attributable to high temperatures in Spain. This study describes the recent evolution of these estimates during the summers of the period 2021–2024.</p> Method <p>We conducted an observational descriptive study using data from MoMo. Population data by province, sex, and age group were obtained from the Spanish National Statistics Institute. Provincial daily maximum and minimum temperature data were provided by the Spanish National Meteorological Agency, following the standard MoMo methodology. Estimates are based on mixed generalised additive models and were described by sex and age groups for the overall country. Geographic patterns were explored by calculating standardized mortality ratios.</p> Results <p>Over the four summers analysed, 11,684 excess deaths attributable to high temperature were estimated by the model, 59.2% occurred in women and 40.8% in men. Excess mortality progressively increased with age, particularly among individuals over 74 years old. The highest number of excess deaths was estimated in 2022. By regions, in 2021, 2022 and 2024 excess of mortality were mainly located in inland provinces, while coastal regions generally showed lower than average risks, except in certain provinces in the East and South.</p> Conclusions <p>MoMo has shown the impact of rising temperatures on excess mortality attributable to high temperatures. It is essential to implement public policies focused on climate change mitigation and adaptation, especially in the most vulnerable populations and in the at-risk areas.</p>