The months of July and August 2025 in Portugal were marked by several warnings of high temperatures that coincided with a significant increase in mortality.
According to data analysed by the Público newspaper from the Death Certificates Information System (SICO), there were 20 consecutive days of excess mortality between July 27 and August 15, resulting in 1,331 deaths, a relative increase of 25%.
According to the Directorate-General for Health (DGS), excess deaths occurred in all regions of the country, but with a higher incidence rate in the north, central areas and the southern region of Alentejo.
The health authority said that high temperatures were the main factor, fuelling dehydration and aggravating chronic diseases, especially cardiovascular and respiratory diseases, in the most vulnerable people.
Data from the Dr Ricardo Jorge National Health Institute shows that this excess mortality was observed mostly among older people.
Of the 34 days of excess mortality recorded in July and August, 29 corresponded to higher than expected deaths in the over 70 age group.
The DGS says that the age group of 75 and over, with the highest burden of disease and the lowest physiological response capacity to heat, were the hardest hit.
The month of July was particularly critical, with two hot spells (July 1 to 9 and 25 to 31).
The Portuguese Institute for the Sea and Atmosphere (IPMA) confirmed that it was the 9th hottest July since 1931, “with air temperature values more than 3°C above the monthly average on the 3rd, 4th, 30th and 31st.”
Despite the excess mortality, the accumulated data up to 18 August shows that the total number of deaths (77,292) is in line with the same period in 2024 (76,849).
However, this year it was July that stood out for its high figures, whereas in the previous year the peak in mortality had occurred in January, coinciding with the end of the flu epidemic period.