Lorraine Williamson
The extraordinary figure means that approximately two out of every three days during the meteorological summer were affected by extreme heat, according to new data released by Spain’s state weather agency AEMET on Wednesday.
The average temperature across Spain during June, July and August reached 24.5°C, making summer 2026 the hottest since the national series began in 1961. It was 0.3°C warmer than the previous record, set only last year, and 2.4°C above the 1991–2020 average.
AEMET says the ten hottest summers in the historical series have all occurred during the 21st century, while seven of the eight hottest have been recorded since 2015.
Record 61 days under heatwave conditions
The most striking feature of summer 2026 was not only the temperature reached, but how long the extreme heat persisted.
Across mainland Spain and the Balearic Islands, AEMET recorded 61 days under official heatwave conditions, easily exceeding the previous record of 41 days in 2022. Last summer, 2025, recorded 36.
Those 61 days were spread across four separate heatwaves during the summer.
The first ran from 20 to 27 June, lasting eight days and affecting 42 provinces. It became the third most geographically widespread heatwave in AEMET’s records, behind only those recorded in July 2022 and July 2024.
A second heatwave lasted from 2 to 24 July and affected 37 provinces. With temperatures 3.9°C above the relevant threshold, AEMET classified it as the most intense heatwave of the summer.
That was followed almost immediately by another prolonged period of extreme heat between 28 July and 20 August, affecting 32 provinces.
The July and August heatwaves lasted 23 and 24 days respectively, making them the third and second longest recorded in Spain since at least 1975. Only the 26-day heatwave of July 2015 lasted longer.
Summer heat continued into September
The exceptional temperatures have not been confined to the traditional summer months.
AEMET says temperatures more typical of July were already being recorded across large areas of Spain at the end of May. Then, after the official meteorological summer ended on 31 August, another heatwave developed in September.
Provisionally classified as running from 2 to 7 September, that episode lasted six days and affected 16 provinces.
It was only the fifth September heatwave identified in AEMET’s historical records, following previous events in 1987, 1988, 2006 and 2016.
The Canary Islands experienced a separate heatwave between 1 and 5 August, affecting both provinces.
What counts as an official heatwave in Spain?
AEMET uses specific criteria when determining whether a period of unusually high temperatures should officially be classified as a heatwave.
For its climatological records, temperatures must exceed the 95th percentile of the highest maximum temperatures recorded during July and August in the reference period at at least 10% of the weather stations considered. Those conditions must persist for at least three consecutive days.
That distinction is important because periods of very hot weather are not automatically classified as heatwaves.
The final figures for summer 2026 show that this year was exceptional not only for individual temperature peaks, but for the persistence of extreme heat across large areas of the country.
With 61 days under heatwave conditions and the country’s summer temperature record broken for the second consecutive year, 2026 has established a new benchmark in Spain’s temperature records.