Overview

• By August 18, 2025, extreme temperatures had already caused more deaths in Spain than during the whole summer of 2024, according to aggregated reporting from official monitors.
• In the Valencian Community, 309 deaths were attributed to temperature effects through August 20, the highest summer total in a decade, based on ISCIII’s MoMo index.
• MoMo estimates deaths tied to extreme heat episodes above location‑specific thresholds, whereas CSIC’s MACE also attributes deaths to repeated periods of moderate heat, yielding higher totals.
• The majority of heat‑attributable deaths stem from the worsening of chronic circulatory, neurological and renal conditions, with people over 65 disproportionately affected.
• Researchers emphasize housing upgrades, reduced energy poverty, urban greening, mobility changes, and targeted education to lower heat risk rather than relying on more alerts.