The hot summer has left its mark: the Mediterranean and the Black Sea are both unusually warm.

Particularly around Italy and south of France, the water temperature is 4 to 5 degrees above the long-term average (1991–2020). Only in the far west and east of the Mediterranean are the anomalies significantly smaller.

As autumn approaches, the warm water could become a problem. If low-pressure systems carrying colder air move across the region, severe thunderstorms and heavy rain may develop leading to inevitable flooding.

Low-pressure systems can absorb a particularly large amount of moisture above very warm water. At the same time, the significant temperature difference between the water and the air provides additional energy, and further fuels severe weather.