Italy to place all 27 of its major cities on highest heat alert

Move comes as fourth heatwave of summer intensifies, edging temperatures in some areas close to 40C

Italy is to place all of its 27 major cities, from Trieste in the north to Palermo in the south, under the highest heat alert as the fourth heatwave to hit the country this summer intensifies.

A red alert means there is a higher chance of an emergency owing to the health risk posed by prolonged extreme temperatures to the entire population.

Twenty-five cities were on red alert on Wednesday, with two more to be added on Thursday, the health ministry said. It is the first time this year that all 27 cities monitored by the health ministry’s heat surveillance system have been placed on maximum alert.

The cities on red alert are: Turin, Bolzano, Milan, Genoa, Venice, Verona, Trieste, Bologna, Florence, Perugia, Rome, Naples, Ancona, Pescara, Bari, Campobasso, Reggio Calabria, Palermo and Cagliari as well as Catania, Messina, Brescia, Viterbo, Latina, Rieti, Frosinone and Civitavecchia.

As temperatures in some areas of Italy have edged up towards 40C in recent days, authorities have warned people to avoid direct sunlight between 11am and 6pm, to stay indoors where possible and drink at least 1.5 litres of water a day. Other guidelines include avoiding fizzy drinks, coffee, alcohol and heavy meals, wearing light clothes and never leaving children or animals in cars.

The extreme heat, which scientists say is driven by the human-caused climate crisis, is not forecast to let up for at least a week. Europe has warmed about twice as fast as the global average.

The current heatwave has been linked to four deaths in recent days, including a 19-year-old tomato-picker and a 40-year-old carpenter, who were both working in industrial areas of the Lombardy region. A security guard in Bologna is thought to have suffered a fatal heat-related illness while in his car.

This year’s heatwaves have also exacerbated a drought in the Po valley, home to Italy’s longest river, after a dry spring. More than 100 towns across Piedmont and Lombardy are dealing with water supply difficulties, with some using tanker trucks to fill drinking water reserves.

The drought is putting a severe strain on Italian agriculture, with farmers saying the extreme heat is affecting crop yields. The heatwaves have also accelerated grape ripening in some areas, while milk production has fallen by 10% owing to dairy cows eating less because of heat stress.

Lorenzo Giovannini, an atmospheric physicist at the University of Trento, told Ansa news agency the heatwaves this summer were already above average compared with previous years for their intensity and duration. He said that although it was difficult to predict when each heatwave would occur, the climate crisis was making them “longer and more intense”.

Major tourist cities, such as Rome, are striving to mitigate the impact of the heat by providing free access to air-conditioned cinemas and cultural venues during the hottest hours of the day, and extending the opening hours of monuments including the Colosseum and Pantheon to allow for evening visits.