Add the Gazzetta del Sud as a source
On Saturday in Messina the maximum will drop to 28 degrees. It is not the arrival of the cool weather – the average September climate in the city is around 27.7 degrees – but the end of the anomaly that has accompanied the last few weeks. What changes, more than the temperature, is what moves below: the Mediterranean remains exceptionally warm and, according to the Cnr, new severe marine heat wave nuclei have formed in the Strait of Sicily. It is the factor that can make the showers expected from Friday more energetic.
What happens at the Strait
Today 3bmeteo forecasts sunshine for the whole day in Messina, without rain, with a maximum of 32 degrees, a minimum of 24 and a sultry warning. On Friday the summer still resists, with the maximum around 31 degrees, while cooler Atlantic currents will reach the South bringing showers and thunderstorms progressively extending to Calabria and Sicily. To date, the anticyclone has also guaranteed stable conditions in Campania, with peaks of 34-36 degrees in the internal areas of the island and locally even further. The same source warns that the trend remains to be confirmed in the next updates: on the hourly detail it is best to wait for the bulletins on Friday morning.
The sea that does not cool
The analyzes of the LaMMA-Cnr Consortium released on 1 September photograph a basin in exceptional conditions. July 2026 was the warmest since 1993 in the Mediterranean, with an average sea surface temperature of around 27 degrees, and 79 percent of the basin experienced a “strong” or greater marine heat wave for at least one day. At the end of August the picture became more uneven: the Mercator Ocean bulletin of 29 August reports an attenuation between Gibraltar and the Balearics, but also new severe nuclei in the Strait of Sicily and in the Adriatic. For this reason, the Cnr invites us not to talk about a uniformly boiling Mediterranean, but rather about a large accumulation of heat with still relevant anomalies.
The heat that stays deep
The anomaly does not only concern the surface. An initial analysis on the Ligurian Sea indicates, compared to July 1993-2016, an excess of heat of approximately 1.7 degrees in the layer between zero and seventy meters. This excess heat represents a quantity of energy estimated at 8.2 exajoules: as an order of magnitude, approximately 1.8 times the energy available for Italy’s final consumption in 2024. An anomaly that also affects deep waters, he adds, lasts longer than subtle surface heating.
«Vigilance, not alarm»
The warm sea releases more heat and water vapor to the lower layers of the atmosphere, increasing the available humidity and energy. However, it is not enough to automatically generate more numerous or stationary storms, because configurations capable of lifting the air are needed: the sea, specifies the CNR, “can however amplify the episodes”. Hence the organisation’s indication, which speaks of attention and updates and not of a general alert. Regarding autumn, the update from the Copernicus Climate Change Service of 10 August indicates high seasonal temperatures over much of Europe, including Italy, with precipitation more likely in the southern and western sectors of the continent. But “it is not possible to make a reliable forecast of a rainy autumn”, warns Meneguzzo.