Spain’s summer heatwaves have intensified over the past five decades, with official figures showing sharp increases in duration and severity. The AEMET study 'Olas de calor en España desde 1975' found that the number of heatwave days has more than doubled, while extreme temperatures have shifted into a more concentrated period. The traditional warning calendar, once a reliable guide for residents, no longer aligns with the periods of highest risk.
Spain typically experiences its most punishing heat between July 15 and August 15. In recent years, but, dangerous temperatures have arrived earlier and lasted longer. The latest data shows that the country entered this critical period after two major heatwaves, with 1,682 deaths attributed to heat-related causes. Meteorologists warn that Mediterranean regions are especially vulnerable. Forecasts point to further temperature spikes driven by hot, dry air masses from Africa.
AEMET’s monitoring system provides hourly station observations and daily summaries, including maximum-temperature readings. Its Meteoalerta warning system covers adverse weather forecasts up to 72 hours ahead. Together, the tools give authorities and residents operational information about recorded conditions and near-term hazards as the heat develops.
Mortality statistics from the Instituto de Salud Carlos III show the growing impact. May recorded 123 heat-related deaths. The toll reached 1,031 in June, then rose by another 622 fatalities during the first week of July. These figures suggest that much of the expected toll for a typical summer has already been reached, even before the most dangerous phase begins. Temperatures in provinces such as Lleida and Zaragoza have approached 40°C, while Valencia narrowly missed that mark.
Forecasts indicate that temperatures in several areas could approach historical records in the coming days. The risk of so-called 'tropical nights', when temperatures remain uncomfortably high after sunset, is also increasing. It remains uncertain whether Spain will see the mercury reach 45°C, but current trends and Saharan dust in the atmosphere mean the possibility cannot be ruled out.
This shift in heatwave patterns has practical consequences for public health and daily life. The gap between the traditional alert calendar and actual risk periods means residents and authorities must adapt their prevention and response strategies. The situation echoes challenges in other recent emergencies, such as the wildfire crisis in Almería, where authorities had to adjust their response to rapidly changing conditions. The issue is explored in this report on the Los Gallardos fire.
Spain’s experience reflects a broader trend of rising temperatures across southern Europe. Heatwaves are now recognized as a major public health threat, with vulnerable populations, including the elderly and people with chronic illnesses, at particular risk. The government and local authorities have expanded early warning systems and public information campaigns, but the rapid pace of change may leave traditional measures insufficient. As the country braces for another round of extreme heat, updated strategies and greater public awareness are increasingly urgent.
