Breaking records under clear skies: the impact of sunshine duration and atmospheric dynamics on the 2024 Eastern European extreme summer temperatures

Abstract The summer of 2024 marked an unprecedented climatic milestone, with global temperatures surpassing the 1.5 °C threshold above pre-industrial levels. Eastern Europe emerged as the epicenter of unprecedented heat, with maximum temperatures exceeding climatological norms by over 5 °C. In this study we show that this record-breaking event (TX—17% explained. variance) was driven by the compound influence of atmospheric blocking (Z500—~12% explained variance), exceptional sunshine duration (SD—13% explained variance), depleted soil moisture (SM—13% explained variance), and elevated nighttime temperatures (TN—18% explained variance). Using a novel integration of statistical methods, we establish both co-variability and causality between these drivers and temperature extremes. Moreover, reduced aerosol concentrations and a decline in total cloud cover further amplified local surface warming. These results emphasize the increasing vulnerability of Eastern Europe to extreme heat events, underscoring the urgent need for climate adaptation strategies and policy interventions to mitigate future risks.