Copernicus report for Western Europe: June and July record warm months

Temperature minima al mare altissime, ecco perché succede e perché conviene andarci a maggio o giugno: l’intervista a Luca Mercalli The Mediterranean Sea has recorded unprecedented temperatures this summer, with coastal minimums reaching levels that make sleeping difficult. According to climate scientist Luca Mercalli, president of the Italian Society of Meteorology, these high nighttime temperatures are linked to the ocean’s role as a massive thermal reservoir. The sea takes time to warm up but retains heat for months, especially as global warming continues to raise its depths. Data from the Copernicus satellite system show that the Mediterranean is currently three degrees above average, storing immense energy. When surface waters reach 30 degrees Celsius, coastal minimums become extremely high, creating uncomfortable conditions for visitors. Mercalli explains that the difference between a night-time temperature of 20 and 27 degrees can have profound effects on human health. He suggests that visiting the coast during May or June might be more comfortable, as water temperatures remain cooler following winter. This advice comes amid growing concerns over the increasing frequency and intensity of heatwaves. While some media outlets have raised alarms about an impending "coldest summer," experts argue that such claims often stem from isolated weather events rather than long-term trends. The summer of 2026 appears poised to surpass the record-breaking heat of 2003, according to atmospheric physicist Lorenzo Giovannini of the University of Trento. Although final data will be available after August, current anomalies suggest that temperatures in many parts of Italy could exceed those of 2003. Giovannini notes that extreme heat was once considered rare but is now becoming routine. The 2003 heatwave was extraordinary both in Italy and France, yet recent years have brought increasingly frequent similar events. This year, however, the situation seems even more severe, with some areas experiencing temperatures previously unheard of in mountainous regions. In northern Italy, particularly in the Veneto and Lombardy regions, the persistence of high temperatures has rewritten local climate records. For example, in the Val d’Adige, days with temperatures exceeding 35 degrees have already surpassed ten, with some locations recording over 15 such days, a figure once unthinkable for Alpine areas. More concerning is the phenomenon of "tropical nights," where minimum temperatures rarely drop below 20 degrees, preventing buildings from cooling down. In Chioggia, on the Venetian coast, minimum temperatures have reached nearly 30 degrees, values typically associated with daytime highs. These extreme conditions are exacerbated by the Mediterranean's transformation into a vast energy storage system. As the sea absorbs and holds heat throughout the summer, it becomes a powerful contributor to heatwaves. When cold air masses arrive in autumn, this stored energy may manifest as intense weather events, including thunderstorms and heavy rainfall. Giovannini warns that future summers could bring even more severe heatwaves, making this one potentially the coolest of the next 30 years. Meanwhile, the monitoring of ocean temperatures has taken new steps. The buoy at Capo Mele, near Savona in Liguria, has been upgraded with advanced technology capable of measuring sea surface temperatures up to 35 degrees. Previously limited to 29.9 degrees, the new system allows for more accurate tracking of rising Mediterranean temperatures. On August 3, 2026, the buoy recorded a reading of 30.3 degrees, the highest ever measured for that area. This upgrade reflects the urgent need to better understand and respond to the impacts of climate change on marine environments. As the summer progresses, there are brief periods of relief, particularly in the central-eastern Alps, where localized thunderstorms may occur. However, these intervals are likely to be short-lived, as the dominant anticyclone from Africa returns to cover much of Italy. Long-term projections indicate that heatwaves will continue to grow in intensity and duration, reinforcing the necessity for sustained efforts to mitigate climate change.