MADRID, Spain (AFP) — The number of heat-related deaths in Spain between May 16 and September 30 hit 3,832, an 87.6-per cent increase from the same period in 2024, the health ministry said Thursday.

Nearly two-thirds of the deaths involved people over the age of 85, and almost 96 per cent were over 65, it said in a statement.

The figures were “estimated through statistical models”, the statement said, adding that the figures may still be revised.

The ministry used data from Spain’s Mortality Monitoring System (MoMo) which tracks daily mortality nationwide and compares it to historical trends.

It also incorporates external factors, such as weather data from the national meteorological agency AEMET, to assess likely causes of mortality spikes.

Although MoMo cannot confirm a direct cause between deaths and high temperatures, it provides the most reliable estimate of fatalities in which heat was likely a decisive factor.

Scientists have warned persistently that human-driven climate change is resulting in more frequent and intense weather events worldwide.

Spain this year sweltered through its hottest summer since records began in 1961, with an average temperature of 24.2C, according to AEMET.

Of the 90 days of summer, 33 were marked by heatwaves, AEMET said.

The country endured a 16-day heatwave in August which fuelled wildfires that killed four people and destroyed a record area of land.

Nine of the 10 hottest summers in Spain since 1961 have occurred in the 21st century, according to AEMET.

Britain, Japan and South Korea also endured the hottest summers this year since each country began keeping records, according to their weather agencies.