The Iberian Peninsula and the Balearic Islands do not have a tropical climate. Under the usual definition, the average temperature in the coldest month would need to reach at least 18°C, a threshold that Spain’s winters do not meet. However, the Mediterranean basin has shown signs in recent decades of moving toward conditions with some tropical-like features.
The clearest signals include rising air and sea temperatures, shifting pressure systems and more erratic rainfall. Air temperatures have increased faster than the global average, shortening winters while extending summers. Spring is arriving earlier and autumn is starting later, even though the transitional seasons have not disappeared entirely.
Mediterranean waters have also warmed significantly, both near the surface and at depths of around 100 metres. On some recent summer days, water temperatures south of Mallorca exceeded 30°C, comparable to or higher than temperatures recorded in the Caribbean and the Gulf of Mexico.
At the same time, major wind belts and pressure systems in the Northern Hemisphere appear to be moving northward. The expansion of the Hadley cell, a large-scale tropical atmospheric circulation, is considered one possible explanation. If this pattern becomes established, atmospheric stability could increase across the Mediterranean, producing longer dry periods interrupted by intense rainfall.
Warmer water can also provide one of the ingredients needed for hurricane-like systems. Surface temperatures of around 26.5°C are generally required for such systems to develop, and large parts of the Mediterranean exceeded that level during the summer. Warm water supplies moisture and latent heat, helping fuel powerful convective storms and torrential rain.
For decades, low-pressure systems known as medicanes have occasionally formed in the Mediterranean. These systems can have a warm core, a defined eye and spiral cloud bands, along with strong winds and heavy rainfall. Their recorded number is close to 100, although changing definitions mean the historical record needs review. As a result, it remains difficult to determine whether medicanes have become more frequent as temperatures have risen.
Not every recent extreme rainfall event is a medicane. Torrential storms in Catalonia in early October 2026 were sometimes described in those terms, but they lacked an eye, spiral cloud structure, significant winds and the low-pressure development associated with a medicane. Instead, several convective cells and mesoscale convective systems behaved in highly unusual ways. Further research is needed to establish whether such events are part of the Mediterranean’s broader tropicalization.
Rainfall along the Mediterranean coast can result from several interacting processes, including cold-drop events, persistent easterly winds, cyclogenesis over the sea and mesoscale convective systems. The region’s complex geography and weather patterns make the intensity and movement of storms particularly difficult to forecast.
This unpredictability appears to have become more pronounced in recent years, especially after the sharp increase in global temperatures from 2022 onward. Forecasting services may need to refine their models and procedures, focusing more closely on local and intermediate scales and on the additional energy stored in warmer Mediterranean waters. Public observations could also complement official measurements through stronger citizen-science initiatives.
Sources: Phys.org.