"We are in a more energetic atmosphere." This is how the spokesperson for the State Meteorological Agency (Aemet), Rubén del Campo, summarizes the reason why torrential rains are increasingly intense and discharge a greater amount of water in less time. Clear examples of this aggressive form of rain that is becoming more common are the recent flood recorded in Madrigueras (Albacete), the largest in the last 50 years that took the life of a centenarian neighbor and left considerable material damage, or the one described as a "mini-hurricane" in Catalonia, which meteorologists believe could have been the beginning of the first tropical cyclogenesis in history throughout the Mediterranean, with records of almost 300 liters per square meter in some points.
"Basically what is happening is that both the atmosphere and the oceans are experiencing warming, which has also been accelerating in recent years. Over the warmer oceans, there is greater evaporation of water (hot water evaporates faster than cold water) and, as there is greater evaporation, there is greater availability of water in the atmosphere for when there are favorable atmospheric conditions for rain, such as a cold front, a trough or a DANA," Del Campo explains to 20 minutes.
In these atmospheric situations, the meteorologist continues, "what makes the sea hotter is to provide more energy, that is, there is greater atmospheric instability, there is a greater contrast between the temperature of the sea surface and the temperature of the upper layers of the atmosphere, and this makes the storm clouds that form more powerful, larger in size, more energetic, capable of generating more torrential rain and adverse phenomena associated with rain or storms, such as hail. or very strong winds or tornadoes.
Del Campo adds one more factor: the temperature of the atmosphere, which is increasingly hotter. "A warmer atmosphere is capable of holding more water vapor. It is a system that is fed by these two aspects: the sea, being warmer, evaporates more water; and simultaneously, the atmosphere, being warmer, is capable of holding all that water vapor. In short, when there is a favorable episode for torrential rains, there is much more water available for it to rain heavily."
According to the latest data from the Copernicus Climate Change Service (C3S), September 2026 was the second warmest September ever recorded globally, behind only 2023. The global average surface air temperature was 16.27°C (1.63°C above pre-industrial level). Additionally, the average sea surface temperature was 21.05°C, the highest ever recorded for September. This value surpassed the previous record for that month, of 20.92°C, established in 2023.
In this context, eltiempo.es meteorologist Mar Gómez agrees with the Aemet spokesperson when explaining the reasons for the extreme rain episodes. "The first thing we must understand is that torrential rains are not a new phenomenon in Spain, although their intensity and frequency are. Our country, and especially the Mediterranean slope, has always been exposed to episodes of very intense rainfall. What is changing is the climatic context in which they occur. A warmer atmosphere has the capacity to contain approximately 7% more water vapor for each degree of warming, following the Clausius-Clapeyron relationship. This does not mean that it will rain 7% more everywhere, but when the right weather conditions exist, storms can have a greater amount of humidity and produce more intense precipitation," says the doctor in Physics.
A warmer atmosphere has the capacity to contain 7% more water vapor for each degree of warming
Added to this is the warming of the Mediterranean, which can favor – Gómez continues – greater evaporation and provide humidity and energy to the atmosphere. "And there is another important aspect: the risk does not depend only on how much it rains, but also on where and how it does so. Urbanization, soil waterproofing and the occupation of flood-prone areas can turn an intense storm into an emergency with enormous consequences," he warns.
One more expert, CIDE-CSIC meteorologist Carlos Calvo-Sancho, provides this newspaper with the same explanation: "What is favoring the greater intensity of storms in recent years is fundamentally greater energy in the atmosphere, and this comes from both the temperature of the sea, the Mediterranean, and a higher air temperature, which allows it to contain a higher moisture content. That is, between the warmer Mediterranean and higher temperatures, this allows for a greater amount of potential energy available for development. of these convective systems".
Point of no return?
Calvo-Sancho, who is a postdoctoral researcher at Climatoc-Lab, a group that studies meteorology at the Desertification Research Center (CIDE), a joint center of the Higher Council for Scientific Research (CSIC), the University of Valencia and the Generalitat Valenciana, points out that "different studies are needed" to confirm that a point of no return has been reached in terms of torrential rains. "What is proven is that since 2022 the heat waves are increasingly more intense and persistent, and this in turn causes the Mediterranean to heat up more. And the moment we have a disturbance at altitude so that this type of storms can form, they become more intense. But that a point of no return has been broken, those are big words," he clarifies.
In recent years we are seeing summers that were unimaginable in the 20th century.
In this sense, Del Campo adds that "we are at a point of accelerated warming. In recent years we are having summers that in the 20th century were unimaginable. Although science told us that these types of summers were going to arrive, it seemed something distant to us. But they are already here. Summers like this year's, which have lasted almost five months, with heat waves that have lasted a total of almost 60 days, and with a warming of the oceans and our own Mediterranean breaking records. Is this irreversible? Still We can mitigate the worst effects of climate change if there is a drastic reduction in greenhouse gas emissions, at least we will ensure that warming does not continue to accelerate. This will somehow allow us to gain time to adapt, because adaptation is already essential. The Aemet spokesperson assures that we have to adapt to extreme torrential rains and that "the window to mitigate them is becoming smaller and smaller."
Along the same lines, Gómez adds that there are changes that we will not be able to reverse on a human scale, but he still considers that "much larger impacts can be avoided." "Future warming depends fundamentally on the greenhouse gas emissions that we continue to accumulate. If we manage to quickly and sustainably reduce CO₂ emissions until we reach net zero emissions, we will be able to approximately stop the further increase in global temperature in the long term. Every tenth of a degree matters. A planet that warms by 1.5 °C is not the same as one that reaches 2 °C or 3 °C," he recalls.
It rains the same but in a different way
The trend shows that the total amount of rain precipitated during the whole year in Spain is "more or less the same since the beginning of the 20th century", however, "how it rains is changing: we are already observing - and this is what the projections for the future indicate - that the rains are concentrated in shorter periods and the droughts are lengthening." According to data provided by the Aemet spokesperson, half of all the rain that fell in 2026 in Spain occurred "in six weeks, between the end of January and March." In this way, water is "less useful and beneficial" that causes "more damage than anything else" by eroding land, destroying infrastructure or even causing human harm.
Experts remember that in the Mediterranean there have already been so-called 'medicanes' (a term that comes from combining the English term hurricane and Mediterranean) with tropical characteristics. However, these phenomena "are not tropical cyclones in themselves, but rather systems that share some of their own features." Del Campo points out, along the same lines as his colleague Calvo-Sancho, that "a hypothesis that must be studied is whether precisely because of the temperatures that the Mediterranean reaches (and that it will reach in coming years) it will be possible to see atmospheric systems with tropical features." The CIDE-CSIC expert specifies that the intense rains recorded at the beginning of the month in the province of Barcelona, called a "mini-hurricane" by President Salvador Illa, could correspond to the "beginning of a pure tropical cyclogenesis in the Mediterranean. Something never seen before." While science confirms this "hypothesis" or not, this expert does not rule out seeing hurricanes in our country: "We will see in the coming years."
