Weather conditions conducive to wildfires have worsened significantly in Spain and France

The research is based on robust and recognised international datasets, such as the ECMWF’s ERA5 reanalysis and climate data from NOAA. The findings are consistent with global evidence that climate change is leading to weather conditions that are fuelling increasingly extreme wildfires in various parts of the world. It confirms the trends showing that droughts and heatwaves amplify the risk. Furthermore, it expands on existing knowledge by directly linking the interannual variability of fire risk in southern Europe to large-scale climate patterns, specifically the North Atlantic Oscillation (NAO) and the El Niño–Southern Oscillation (ENSO).

Although the researchers themselves point out certain limitations due to a lack of data harmonisation, the reliance on the analytical methods used, and uncertainty regarding the ability of current climate models to predict future changes, the data do indicate that there has been a shift in fire patterns in recent years, requiring new strategies that include prevention. Furthermore, there is a need to explore new predictive systems. Likewise, the study highlights the need for reliable and interoperable data.

The implications are critical, as the Iberian Peninsula, and Spain in particular, is the most severely affected region, accounting for a high percentage of the area burnt in southern Europe during the catastrophic 2025 season and the trends observed in 2026.

The article analyses the main meteorological variables underlying major forest fires, using the situation experienced in southern Europe in 2025 as a case study. It explains the downward trend in the area burnt and the number of fires over recent decades, alongside the increase in meteorological fire risk. The study examines the global effect of ENSO and the regional effect of the NAO on the variability of the FWI (Fire Weather Index), finding an anti-correlation between the NAO and the FWI in some areas of southern Europe, but not in the north-west of the Iberian Peninsula, where FWI variability appears to be related to ENSO anomalies in region 1+2, associated with La Niña. These relationships are statistical and do not in themselves demonstrate a causal link.

The study highlights the difference in fire regimes between the more Atlantic and the more Mediterranean regions, particularly on the Iberian Peninsula, which calls for differentiated strategies tailored to each context. In both contexts, the intensification of meteorological conditions increases the likelihood that some fires will exceed the capacity of the fire-fighting system, highlighting the need for a paradigm shift in risk management.

Limitations: the variables studied are purely meteorological and do not directly incorporate fuel characteristics; although the FWI estimates the moisture content of dead fuel, it does not include its quantity, structure or continuity. Only the high rainfall and the resulting vegetation growth in the spring of 2025 are mentioned in qualitative terms. Apart from surface conditions, recent scientific literature on extreme fire behaviour also includes the vertical structure of the atmosphere and the interaction between fire and the atmosphere as key factors in the behaviour and spread of forest fires, particularly in southern Europe.

This study scientifically confirms and demonstrates a phenomenon that, particularly in recent years, we have been observing both in southern Europe and in other regions of the world: increasingly extreme conditions of heat, drought and wind are fuelling large-scale forest fires (which, by definition, are those covering an area of more than 500 hectares, sometimes reaching several tens of thousands). Once started, they spread at great speed and become uncontrollable, overwhelming the emergency response operation deployed to extinguish them.

The researchers behind this study, following a detailed analysis of climatological data, have found that the meteorological conditions conducive to a fire, once started, spreading uncontrollably and reaching enormous proportions – thereby creating its own weather system – have occurred much more frequently in certain areas of Spain and France over the last decade, compared with the normal period from 1981 to 2010. They link this new fire behaviour to changes taking place in the weather patterns affecting us, fuelled by the current context of global warming. Studies such as this are increasingly necessary to better understand how the global rise in temperatures is linked to global and regional atmospheric circulation, which can help us to better anticipate the impacts of extreme weather events, of which these mega-fires are one manifestation.

The article provides some very interesting and valuable information on a topic of the utmost interest: the impact of climate change on the forest fires ravaging southern Europe. Whilst it is generally well known that global warming leads more frequently to conditions conducive to forest fires – as noted by the IPCC in its Sixth Assessment Report – this article presents figures that must be taken into account when managing firefighting efforts: such conditions have intensified by 50 per cent over the last decade compared with the period between 1981 and 2010, and the number of days with such conditions has also increased. Specifically, the study puts the increase at around 15 days. It should be noted that the State Meteorological Agency estimates, in its latest report on Spain’s climate, that the number of days under heatwave conditions in our country is increasing at a rate of three additional days per decade, so the correlation is clear.

There are many facets to the issue of forest fires, and forest management and the accumulation of plant matter—which subsequently acts as fuel—are undoubtedly crucial. This study also highlights this, stating that the total number of fires has fallen, probably due to improvements in prevention and pre-fire management. However, anthropogenic climate change also plays a significant role; it can make – and indeed is already making – fire control more difficult because the fires are more virulent due to plant matter that is extremely dry as a result of prevailing weather conditions of extreme heat and drought, which are now more frequent and intense.