Spain experienced its deadliest May on record for heat-related mortality, with 101 deaths attributed to unusually high temperatures, according to the daily mortality monitoring system (MoMo). The figure, released by the Ministry of Health, is 3.6 times the average for May over the past decade and underscores a growing public health challenge as extreme heat arrives earlier in the year.
The deaths occurred before the meteorological summer began, highlighting a shift in seasonal patterns. Health Minister Mónica García, presenting the 2026 National Plan for Preventive Action on the Health Effects of Excess Temperatures, noted: "The problem is no longer just that it is hotter, it is that it arrives earlier and earlier and our bodies have not yet acclimatised. There is a lack of physiological adaptation and there is no perception of the risk this entails."
Rising Mortality Risk with Every Degree
Ministry calculations show that mortality risk rises by between 9.1% and 10.7% for each degree the temperature exceeds the threshold considered risky for health. This statistical relationship, derived from years of data, reinforces the urgency of preventive measures, especially as the World Meteorological Organization warns of widespread above-average summer temperatures across Europe.
Cumulative data from MoMo, which has tracked heat-related deaths since 2015, estimates 27,564 such deaths in Spain between 2015 and 2025. The deadliest year was 2022, with 4,789 deaths, followed by 2025 with 3,832. The 2025 figure already includes the May toll, and summer has only just begun.
The early heatwave also affected coastal waters, with Spanish coastal waters hitting record May temperatures, compounding the environmental and health pressures on the country.
García emphasised that the health system must adapt to this new reality. The 2026 plan includes early warning systems, public information campaigns, and coordination with regional health authorities across Spain's seventeen autonomous communities. The plan also targets vulnerable groups, including the elderly, outdoor workers, and those with pre-existing conditions.
The European dimension is significant. As southern European nations like Spain, Italy, and Greece face increasingly frequent and intense heatwaves, the European Commission has been exploring cross-border health alerts and climate adaptation strategies. Spain's experience may serve as a case study for other member states grappling with similar trends.
In Madrid, Barcelona, and Seville, local authorities have already activated cooling centres and extended public pool hours. The Spanish government has also allocated additional funds to hospitals for heat-related emergencies. Yet the May death toll suggests that current measures may be insufficient for the pace of climate change.
"We are seeing a new pattern," said a spokesperson for the Spanish Meteorological Agency (AEMET). "May temperatures this year were 3 to 5 degrees Celsius above the historical average in many regions. This is not a one-off anomaly but part of a trend."
The health ministry's data also reveals that heat-related deaths are not limited to the hottest days. Mortality spikes occur when temperatures exceed local thresholds, which vary by region. In northern cities like Bilbao and Santiago de Compostela, where populations are less accustomed to heat, even moderate temperature increases can be deadly.
As Europe braces for another potentially record-breaking summer, Spain's May mortality figures serve as a stark reminder that the heat season is lengthening. The challenge for policymakers is not just to respond to extreme events but to build resilience across the continent's diverse climates and health systems.
