Spain has concluded its second-hottest June since records began in 1961, with the State Meteorological Agency (Aemet) classifying the month as 'extremely warm' — a designation reserved for exceptionally abnormal climatic events. The average temperature across mainland Spain reached 23.2°C, a full 3.2°C above the 1991–2020 baseline. Only June 2025, with an average of 23.6°C, has been hotter in the historical series.
The heatwave that struck between 22 and 24 June broke multiple daily records. On 22 and 23 June, Spain experienced its two hottest June days since at least 1950. Aemet described the episode as 'extraordinary' due to its intensity, duration, and geographical spread, particularly affecting the northern half of the mainland, where numerous local temperature records were shattered.
Health Toll and Mortality Monitoring
The extreme heat had a severe impact on public health. The Ministry of Health's daily all-cause mortality monitoring system (MoMo) provisionally estimates nearly 900 deaths attributable to high temperatures during June. More than 600 of those deaths were concentrated in the week of the heatwave. As of Tuesday, the system had recorded 892 excess deaths, making it the second June with the highest heat-related mortality since MoMo began in 2015.
The MoMo system does not directly count deaths certified as caused by heat. Instead, it calculates excess mortality by comparing observed deaths with expected figures for each period and links that excess to episodes of potentially dangerous temperatures. This methodology provides a robust estimate of the broader health impact of extreme heat events.
This trend is not isolated to Spain. Across Europe, heatwaves are testing the resilience of infrastructure and public health systems, raising questions about the EU Green Deal's preparedness for a warming continent.
Earlier and More Frequent Heatwaves
The heatwave that affected much of mainland Spain and the Balearic Islands is part of a clear pattern: heatwaves are not only becoming more frequent and intense but are also arriving earlier in the calendar, effectively prolonging the summer. Aemet data show that between 1975 and 2000, only two heatwaves were recorded in June in mainland Spain. Between 2000 and 2025, that number rose to ten.
Experts attribute this shift to global warming driven by greenhouse gas emissions, primarily from fossil fuel use. The fact that the two warmest Junes in the historical series have occurred in the last two years reflects a global trend where temperature records are being broken with increasing regularity, and recent years consistently rank among the hottest ever recorded.
This acceleration in warming has implications beyond Spain. Swiss glaciers are experiencing record early melt, and record ocean heat threatens Europe with sea level rise and extreme weather. The interconnected nature of these phenomena underscores the urgency of climate adaptation across the continent.
As Spain braces for further heat, with Aemet warning of a return to extreme temperatures in the coming weeks, the data from June serves as a stark reminder of the human cost of a warming climate. The nearly 900 excess deaths are not just statistics; they represent a public health crisis that demands coordinated action at national and European levels.
