Spain's second-hottest June linked to more than 1,000 heat deaths as heatwave reaches Luxembourg

Spain has attributed more than 1,000 excess deaths to heat during June, the country's second-warmest June since records began in 1961, its weather service and public-health monitors said this week — a toll that lays bare how sharply intensifying European summers now threaten lives, and one driven by the same heat dome that pushed red warnings across Luxembourg and the wider Greater Region.

The MoMo excess-mortality system, run by the Carlos III Health Institute under Spain's health ministry, linked more than 1,000 deaths to the heat over the month — 1,028 in the latest official count, and reported by Reuters at 1,029. That is more than double the 407 heat-attributed deaths recorded in June 2025, and the second-highest June toll since the MoMo series began in 2015. Most of the deaths fell in a single searing week around 22-24 June.

A June like almost no other

The State Meteorological Agency (AEMET) said mainland Spain averaged 23.2°C in June, 3.2°C above the 1991-2020 norm and behind only June 2025, which averaged 23.6°C. The 22nd and 23rd were the two hottest June days in Spain since at least 1950. The wider trend is starker still: the first half of 2026 was the hottest on record nationally, running 1.6°C above normal, and AEMET says its seven warmest first-halves have all landed in the past decade.

Heatwaves are also arriving earlier and striking more often. AEMET recorded just two June heatwaves in mainland Spain between 1975 and 2000; between 2000 and 2025 it logged ten. Roughly half of all the June heatwaves the agency has tracked since 1975 have occurred since 2015.

heatwaves appear at the beginning of summer with a higher frequency than before

That warning came from AEMET spokesperson Rubén del Campo, who has said Spain's summers will keep intensifying as climate change makes heatwaves more frequent, longer and more likely to strike outside the traditional July-August window.

Counting the dead

The mortality figures carry an important caveat. MoMo does not certify heat as a direct cause of death; instead it estimates excess mortality by comparing observed deaths with the number expected for the same period. The gap that opened up in June is attributed to the heat.

The burden fell overwhelmingly on the old. According to the institute's data, the vast majority of the deaths were among people aged 65 and over, with several hundred among those aged 85 and above. Fatalities were concentrated in less heat-acclimatised northern and Mediterranean regions, including Catalonia and the Basque Country, where homes and communities are less prepared for prolonged extreme heat.

The same dome over Luxembourg

Spain was the deadliest front of a heatwave that gripped much of the continent in late June. National temperature records fell in Germany, Poland, the Czech Republic, Slovakia and Hungary; the United Kingdom and Switzerland logged their hottest June days; France recorded its highest-ever nighttime temperatures; and Ireland reached 32.1°C. Scientists at World Weather Attribution said the event would have been "virtually impossible" in June without human-caused climate change.

Luxembourg sat squarely under the same dome. MeteoLux issued an orange heat warning from Friday 19 June, then escalated to a red warning in force from midday on Monday 22 June across the whole country, extending it through the week as temperatures were forecast to reach up to 40°C locally — 36-38°C in the south and 33-35°C in the north. The alert overlapped with National Day celebrations on 22-23 June, drawing large crowds into the heat.

The government's Weather and Flood Risk Assessment Unit (CERI) warned that "the exceptionally high temperatures forecast throughout next week indicate a heatwave of unusual intensity and duration, with an expected impact on the population as well as on the operation of emergency and health services." Authorities urged residents to:

drink at least 1.5 litres of water a day;

avoid outdoor exposure between roughly 11:00 and 21:00;

keep living spaces cool and use shade or air conditioning where possible;

check regularly on vulnerable people — the elderly, the chronically ill and young children.

A warning that travels

Spain's death toll is a preview of a risk the Grand Duchy now shares. The heat that killed more than a thousand people to the south-west is the same weather system that emptied Luxembourg's streets during a red alert. As del Campo and independent climate scientists stress, the pattern is not a one-off: earlier, longer and more intense heatwaves are becoming a fixed feature of European summers, and with them a mounting public-health emergency that reaches well beyond the Mediterranean.