AleaSoft Energy Forecasting, September 10, 2026. Exceptionally high temperatures, wildfires and more than 5400 deaths attributable to temperature once again highlight the need to combine decarbonisation, adaptation and a more resilient electricity system.
A summer marked by historic temperatures
The summer of 2026 is leaving a new set of signals in Spain about the scale of the effects of climate change. Exceptionally high temperatures, historic records, hundreds of thousands of hectares affected by wildfires and a significant impact on mortality show that extreme heat is now an environmental, health, economic and energy problem.
Data from the State Meteorological Agency (AEMET) reflect a summer marked by temperatures well above usual. June was the second warmest since the series began in 1961, with an average temperature in peninsular Spain of 23.3 °C, 3.2 °C above the 1991-2020 average.
July was even more exceptional. With an average temperature of 25.7 °C and an anomaly of 2.6 °C, it matched July 2022 as the warmest July on record. It was also, together with that month, the warmest month recorded in Spain since 1961. These temperatures were accompanied by rainfall of just 26% of the usual amount, making it also the driest July on record.
August maintained this trend, with an average temperature of 24.4 °C, 1.4 °C above the reference average, and ranked as the sixth warmest August since 1961. Nine of the ten warmest Augusts recorded in Spain have already occurred in the 21st century.
September extends the heat and sets new records
The arrival of September did not mean an immediate end to the extreme temperatures. During the first days of the month, exceptionally high values for the time of year were recorded again, and historic records were broken at several weather stations.
Logroño airport reached 40.5 °C, exceeding 40 °C during the meteorological autumn at this station for the first time, comfortably beating the previous September record of 39 °C, set in 1988. Record minimum temperatures were also reached, with nights when thermometers did not fall below 25 °C in some areas.
The Fabra Observatory in Barcelona broke several records during the first days of September, reaching 35.5 °C on the 5th. The previous all-time September high before this episode was 33 °C, dating back to 1983. Catalonia also recorded temperatures above 40 °C in various areas.
At the start of the second week of September, before the arrival of a weather front that caused a drop in temperatures, temperatures in large parts of Spain were still between 5 °C and 10 °C above normal September values.
More than 5400 deaths attributable to temperature
The consequences of extreme heat are not limited to meteorological records. Data from the daily Mortality Monitoring System, MoMo, managed by the National Centre for Epidemiology of the Carlos III Health Institute, also show its impact on health.
According to the data available for the 2026 summer period, MoMo estimates 5485 deaths attributable to temperatures in Spain up to September 9. This is a provisional estimate, since the summer period is still ongoing.
The current 2026 figure is particularly significant considering that, throughout the entire 2025 Heat Plan period, between May 16 and September 30, MoMo estimated 3832 deaths attributable to high temperatures.
Nearly 300 000 hectares burned in Spain
Extreme heat has also coincided this summer with a season of wildfires that has been particularly severe. High temperatures alone do not explain the outbreak of these fires, but combined with a lack of humidity, dry vegetation and certain episodes of wind, they can create very favourable conditions for their spread and make firefighting more difficult.
According to the European Forest Fire Information System, EFFIS, part of the Copernicus programme, by September 2, 295 720 hectares had burned in Spain. This area accounted for 45.6% of all the hectares burned in the European Union since the start of the year.
At the start of July, the cumulative burned area in Spain stood at around 50 000 hectares. The sharp increase that followed reflects the intensity the season reached during the central weeks of summer.
Wildfires cause human, environmental and economic losses, but they also make it necessary to consider the adaptation of infrastructure and territories to increasingly demanding climate conditions.
Decarbonisation and adaptation must advance together
This summer’s data show that climate change is not solely a question of long-term average temperatures. Its consequences already affect people’s health, ecosystems, cities, infrastructure and the electricity system.
Reducing emissions through the electrification of the economy and the development of renewable energies is essential to limit the future rise in temperatures. However, mitigation must advance in parallel with adaptation. Cities will need to be prepared for more intense heat episodes, protection for the most vulnerable population will need to be strengthened, forest management will need to improve, and infrastructure capable of operating safely under increasingly extreme weather scenarios will be required.
The summer of 2026 once again shows that mitigation and adaptation can no longer be treated as separate strategies. In this context, demand forecasts, prices and renewable production, together with storage, flexibility, self-consumption and energy efficiency, will become increasingly important for a decarbonised and resilient electricity system. Accelerating the energy transition will reduce emissions, while anticipating new climate risks will be essential to limit their human, environmental and economic costs.
Forecasting for an electricity system under thermal stress: the role of AleaBlue
For the energy sector, these episodes of extreme heat pose immediate operational challenges. Extreme temperatures increase cooling needs and change the profile of electricity demand, while also subjecting grids and infrastructure to more demanding conditions. Anticipating these effects in the short and mid-term becomes a determining factor for the operation of the electricity system.
AleaBlue, the AleaSoft Energy Forecasting division, specialising in short- and mid-term forecasts, from minutes to three years, produces energy demand forecasting, electricity market price forecasts and renewable production forecasts, essential in the face of extreme weather episodes, providing electricity retailers, traders, utilities and large consumers with consistent forecasts to manage risks and opportunities in a context of greater volatility.
Source: AleaSoft Energy Forecasting