News
Extreme rainfall is intensifying unevenly across the Iberian Peninsula: the Atlantic-Mediterranean contrast
- July 1, 2026
- Meteorology and Climatology
A new study by the Meteorology and Climatology Area, published in Weather and Climate Extremes, explores uneven extreme rainfall intensification in the Iberian Peninsula.
https://doi.org/10.1016/j.wace.2026.100929
The study, entitled “Exploring shifts in extreme precipitation and synoptic forces across the Iberian Peninsula: A regionalized perspective”, analyses the evolution of extreme precipitation events over the past seven decades, combining high-resolution precipitation data with atmospheric reanalysis information to identify the regional atmospheric mechanisms that favour these high-impact events.
Extreme precipitation is one of the most damaging climate-related hazards in the Iberian Peninsula, with direct consequences for flood risk, infrastructure, water resources and civil protection. However, these events do not evolve uniformly across the territory. The Iberian Peninsula lies at the transition between Atlantic and Mediterranean climate influences, which makes it especially important to understand changes from a regional perspective.
To address this challenge, the study identifies eight precipitation-coherent regions across the Iberian Peninsula (Fig. 1) and analyses how extreme precipitation and its associated atmospheric drivers have evolved over recent decades. The results show an overall intensification of regionalized extreme precipitation events, mainly driven by stronger local precipitation rather than by a general expansion of the affected area. This local intensification is particularly marked in southern Mediterranean regions and in the Cantabrian region (Fig. 2).
One of the key contributions of the study is the identification of two distinct evolutionary pathways. In Atlantic regions, extreme precipitation events show a moderate intensification, despite a progressive weakening or northward displacement of the atmospheric disturbances traditionally associated with heavy rainfall. In these areas, stronger air flows and a generalized increase in atmospheric moisture content appear to partly compensate for the weakening of upper-level perturbations.
Mediterranean regions follow a different pathway. Here, the study detects a more marked intensification of extreme precipitation events, associated with changes in atmospheric dynamics that may favour high-impact rainfall. These include an increasing contrast between atmospheric disturbances and their surrounding environment, as well as an enhancement of cyclonic circulation in south-eastern regions. In addition, Mediterranean regions show a noticeable increase in water vapour among the most humid air masses, creating more favourable conditions for intense precipitation when suitable atmospheric dynamics occur.
The results also highlight the particular behaviour of the Cantabrian region, which shows transitional characteristics between the Atlantic and Mediterranean pathways. In this region, the intensification of upper-level flows appears to play a major role in the evolution of extreme precipitation, even without a clear increase in atmospheric moisture.
Overall, the findings demonstrate that extreme precipitation in the Iberian Peninsula is not changing through a single mechanism. Instead, Atlantic and Mediterranean regions are evolving through different combinations of atmospheric dynamics and moisture availability. This regionalized understanding is essential for improving early warning systems, climate risk assessment and adaptation planning.
By identifying where and why extreme precipitation may become more intense, this study provides valuable scientific evidence to support more targeted strategies aimed at reducing the socioeconomic impacts of future high-impact rainfall events in one of the European regions most vulnerable to climate change.
Benetó, P., Valiente, J. A., & Khodayar, S. (2026). Exploring shifts in extreme precipitation and synoptic forces across the Iberian Peninsula: A regionalized perspective. Weather and Climate Extremes, 53, 100929. https://doi.org/10.1016/j.wace.2026.100929
