High summer temperatures claimed the lives of 22 individuals in the Canary Islands during August, according to figures from the Daily Mortality Monitoring System (MoMo) of the Carlos III Health Institute (ISCIII). The majority of the victims were women over the age of 65, a group particularly vulnerable to the effects of extreme heat.
Concentration of Deaths During Heatwave Week
Most fatalities occurred during the week of 11–17 August, when the archipelago experienced an intense heatwave. That week alone accounted for 17 of the 22 deaths, coinciding with the first-ever maximum alert declaration for high temperatures across the Canary Islands.
Of the total, nine were men and thirteen women, with nineteen victims over the age of 65. Deaths were evenly distributed across the two provinces, with 11 in Las Palmas and 11 in Santa Cruz de Tenerife.
The figure aligns with August 2024, when 23 heat-related deaths were recorded. Over the past three months, 59 individuals in the Canary Islands have died due to excessive heat.
National Context: Thousands of Deaths Across Spain
While the Canary Islands recorded relatively few fatalities, the impact nationwide was severe. Across Spain, 2,177 people died in August due to high temperatures—a 71.3% increase compared to August 2024.
- July 2025: 1,060 heat-related deaths.
- August 2025: 2,177 deaths (an increase of 1,117).
- Since June 2025: 3,644 heat-related deaths, 84.3% more than in the same three months of 2024.
By region, the most affected were:
- Madrid (415 deaths)
- Catalonia (361)
- Castile and León (264)
- Valencian Community (204)
- Galicia (198)
- Andalusia (169)
The Canary Islands ranked far lower, with 22 deaths.
By gender, 1,300 women and 877 men died in August due to excessive heat. By age, 2,099 were over 65, including 1,428 over 85 years old.
Why Heat is So Deadly
The Ministry of Health emphasises that extreme heat is closely linked to higher morbidity and mortality rates. Epidemiological studies confirm that heatwaves result in increased deaths from cardiovascular and respiratory conditions.
When exposed to high temperatures, the human body’s thermoregulatory system can become overwhelmed. Possible consequences include:
- Cramps and dehydration
- Sunstroke and heatstroke (with multi-organ complications such as convulsions, loss of coordination, and even coma)
Vulnerability increases with ageing, chronic illnesses, disability, and social factors such as isolation or poverty.
A healthy individual can tolerate an internal temperature variation of about 3°C without severe consequences. Beyond 37°C, however, the body activates defence mechanisms. Older adults and children are less able to adapt, rendering them particularly at risk.
National Plan and Monitoring System
To mitigate these dangers, Spain has implemented a National Plan for Preventive Actions Against the Effects of Excessive Temperatures, coordinated by the Ministry of Health.
The MoMo system, established in 2004, monitors daily mortality across the nation to detect deviations from expected patterns. It provides real-time estimates of excess deaths related to extreme temperatures (both heat and cold), categorised by region, sex, and age group. This monitoring enables public health authorities to respond more swiftly to hazardous weather events.
