Lorraine Williamson
Spain has recorded its highest number of deaths in May that were linked to heat since official monitoring began. This raises fresh concern about the health impact of rising temperatures before the country has entered the peak summer season.
According to Spain’s Ministry of Health, the Daily Mortality Monitoring System, known as MoMo, attributed 101 deaths to high temperatures in May 2026. It is the highest figure recorded for that month since the series began in 2015. It is also 3.6 times higher than the average number of heat-related deaths recorded in May over the past decade.
For residents, tourists, older people and families in Spain, the message is clear. Heat is no longer only a July or August issue. It is becoming an earlier, longer and more serious public-health risk.
Why this matters before summer
The Ministry of Health says the latest figures show why prevention measures need to begin before the traditional summer holiday period. Spain’s national heat-health plan was activated on 13 May and runs until 30 September, although monitoring can be extended from 1 May to 15 October when unusual heat episodes occur.
That flexibility matters. May is still widely seen as a spring month. Yet the 2026 figures suggest that dangerous temperatures can now arrive well before many people have adjusted their habits, homes or routines.
Heat deaths are not always caused by dramatic cases of heatstroke. In many cases, high temperatures worsen existing health problems, place extra strain on the heart and lungs, disturb sleep, increase dehydration and make daily life more dangerous for people who are already vulnerable.
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Spain updates heat-risk thresholds
Sanidad has also updated some of the temperature thresholds used to trigger health alerts. The ministry says the new thresholds follow a review of historic mortality and heat data in Spain.
For the 2026 campaign, the health-risk thresholds were calculated by analysing the relationship between daily deaths from natural causes and maximum daily temperatures. The data series used runs from 1 January 2012 to 31 December 2023, although the years 2020 and 2021 were excluded because the COVID-19 pandemic distorted normal mortality patterns.
The updated system divides Spain into 182 “meteosalud” zones. These areas are designed around similar climate patterns, using adverse weather areas established by AEMET, Spain’s state meteorological agency.
This more localised system is important because heat does not affect every part of Spain in the same way. A temperature that is expected in one province may be unusually dangerous in another, especially in areas where homes, routines and public behaviour have not historically been shaped around extreme heat.
Older people and vulnerable groups face the highest risk
Sanidad says the impact of extreme temperatures is concentrated mainly among people aged over 75. However, babies, children under four, pregnant women and people with chronic illnesses are also at particular risk.
Those chronic conditions include cardiovascular, respiratory and mental health problems. People taking certain medicines may also be more vulnerable, particularly if heat affects hydration, blood pressure, sleep or how medication is stored.
The danger is not limited to people living alone, although isolation can increase the risk. Tourists can also be affected, especially if they underestimate inland heat, spend long hours outdoors, drink alcohol in the sun or walk during the hottest part of the day.
In many parts of Spain, the hottest hours are not the best time to “push through” sightseeing, errands, gardening or exercise.
A decade of rising concern
Between 2015 and 2025, MoMo estimated that 27,564 deaths in Spain were attributable to high temperatures. The worst year in that period was 2022, with 4,789 deaths, followed by 2025, with 3,832.
Sanidad says the risk of mortality rises by between 9.1% and 10.7% for every degree that the temperature exceeds the health-risk threshold.
Those figures help explain why public-health officials now treat heat as more than a weather inconvenience. It is a measurable health threat, and one that can affect hospitals, care homes, workplaces and households.
The challenge is also changing. Spain has long been associated with hot summers, but warmer periods are now arriving earlier and lasting longer. That makes public awareness more important, particularly in May, June, September and even early October, when many people may not yet be acting as if they are in a high-risk heat period.
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What residents and visitors should do
The Ministry of Health is urging people to follow basic prevention advice during hot weather.
People should drink water frequently, even when they do not feel thirsty. Sanidad also recommends avoiding drinks with alcohol, caffeine or too much sugar, as these can worsen dehydration.
During the hottest hours, people should stay in cool or air-conditioned places where possible and reduce physical activity. Medicines should also be kept in cool places so heat does not alter their composition.
The advice is simple, but it matters. Checking on older relatives, neighbours or friends can also make a difference, especially during the first heat episodes of the season, when the body may not yet have adapted.
Heat is becoming a longer season in Spain
The record May figure does not mean every part of Spain is equally affected on the same day. Nor does it mean every hot spell will produce the same health impact.
However, it does show that Spain’s heat-risk season is no longer confined to the height of summer. The warning period now stretches wider, and the health consequences can begin earlier than many people expect. Therefore, it is important to treat early-season heat seriously, follow official warnings, and adjust daily routines before temperatures become dangerous.
Spain’s summer may still be associated with beaches, terraces and long evenings outdoors. But the public-health reality is becoming harder to ignore. Heat is already claiming lives before summer has officially begun.