Soaring heat-related fatalities occurred in Spain during July
In the sweltering summer of 2025, Spain has been grappling with an unprecedented heatwave that has pushed temperatures to historic highs. On August 6, the Spanish Ministry of Health announced the figures, revealing a concerning rise in mortality due to the intense heat.
The "MoMo" system, a tool developed by the Carlos III Health Institute, has been instrumental in calculating the excess mortality. The system collects the number of daily deaths in Spain and compares it to expected mortality based on historical series, taking into account external factors such as temperatures reported by Aemet.
The current heatwave is not directly linked to the recorded deaths by the "MoMo" system, but it could be a contributing factor to the excess mortality in August 2025. The system recorded an excess of 1,180 deaths over the period from May 16 to July 13, a significant increase compared to the 70 deaths observed over the same period in 2024.
The summer of 2025 in Spain has been particularly hot. June averaged 23.7°C, marking it as the hottest month on record. The heatwave reached its peak in July, with temperatures soaring above 40°C in many regions. In fact, Aemet observed a peak of 43.3°C in Granada, while temperatures of up to 42°C were recorded in the west of Spain.
The island of Gran Canaria experienced a maximum nighttime temperature of 31.3°C in Aguïmes in July 2025, highlighting that the heatwave's intensity was not limited to daylight hours. Indeed, the heatwave in the Canaries reached its peak at night.
The intensity of heatwaves has increased markedly, with Spain experiencing temperatures frequently exceeding 40°C. This sharp rise in temperatures has been linked to a significant increase in heat-related deaths, with over 1,180 fatalities reported in just two months in 2025, compared to 70 in the same months the previous year.
Climate change has led to a significant increase in the frequency, duration, and intensity of heatwaves in Spain. Recent data from 2025 shows that heatwaves have become more frequent, with 76 red alerts for extreme heat issued between May and July, compared to none in the same period in 2024. The heatwaves are also longer, such as the prolonged event in August 2025 expected to last over a week with temperatures soaring above 43°C in some regions.
Underlying this trend is the broader effect of climate change that warms the atmosphere, allowing it to hold more moisture and increasing the likelihood of extreme weather events, including intense heatwaves. In addition, urban areas like Madrid experience amplified heatwave intensity due to the Urban Heat Island effect, where city infrastructure retains and radiates heat, making temperatures 8.5°C higher than in nearby rural areas and contributing to more severe heat exposure for urban populations.
Minister of Health, Monica García, emphasized the importance of protecting oneself from heatwaves due to their impact on mortality. As the heatwave in Spain and Portugal, which started on August 3, is expected to last until the end of the week, it is crucial for everyone to take necessary precautions to stay safe in the scorching heat.
The "MoMo" system, developed by the Carlos III Health Institute, has been monitoring the excess mortality following the unprecedented heatwave in Spain. Considering the system's record of an excess of 1,180 deaths from May 16 to July 13, 2025, it's clear that climate change, with its impact on increasing the frequency, duration, and intensity of heatwaves, could be a significant factor in health-and-wellness concerns, particularly environmental-science related issues, such as climate-change induced heatwaves. Understanding and addressing these environmental factors are crucial for minimizing associated health risks.
