Cerberus anticyclone brings extreme heat to Italy: eight cities on red alert, peak midweek

Italy swelters under heatwave

A powerful subtropical anticyclone named Cerberus is driving a prolonged heatwave across Italy and much of western Europe. On Sunday 21 June, eight Italian cities were placed under red alert (the highest risk level) by the health ministry: Bologna, Bolzano, Brescia, Firenze, Milano, Perugia, Rieti and Torino. Another eight cities are under orange alert and eleven under yellow, leaving no monitored urban centre without a warning colour. The same weather pattern triggered yellow thunderstorm alerts for parts of Abruzzo, Molise and Umbria from the Civil Protection, with hail risk in mountainous areas.

Red alert8

Orange alert8

Yellow alert11

Red alert

8

Orange alert

8

Yellow alert

11

Data from the article text

Super tropical nights and temperature records

Meteorologists warn of “super tropical nights” where overnight minimums fail to drop below 25°C, and in some coastal and plain areas may not fall under 27°C. Daytime peaks on Sunday reached 38–39°C across the Pianura Padana and inland central regions, with thermal anomalies of 10°C above the 1991–2020 average. Lorenzo Tedici of iLMeteo.it notes that compared to the 1961–1990 baseline the anomaly would be 10–13°C. The heat is expected to persist, with no relief in sight for at least ten days.

“At the moment no way out is seen for the next ten days.”

Health warnings and historical context

The health ministry stresses the dangers: heatwaves are a climate emergency with the greatest impact on public health. Every year brings increased mortality and hospital admissions, with people suffering from cardiovascular, respiratory, metabolic and neurological conditions at particular risk.

“Heatwaves represent one of the climate emergencies with the greatest impact on public health. Every year an increase in mortality and hospital admissions is observed. Particular attention must be paid to people suffering from cardiovascular, respiratory, metabolic and neurological diseases.”

Last year Italy experienced its second-warmest June on record, with a +3.02°C anomaly against the 1991–2020 average, while August of the same year was only +0.69°C above average. The current heatwave is attributed to subtropical air masses from North Africa, not El Niño, and forecasts indicate summer 2026 will be 1–2°C warmer than normal across the country.

June3.02

August0.69

June

3.02 °C

August

0.69 °C

Data from the article text

Europe also under pressure

France and Spain face even more severe conditions. In Andalusia temperatures reached 45°C, while Lyon and Bordeaux hit 38°C and Paris 37°C on Saturday. Thirty-five French departments were under red alert on Sunday. Heat alerts also cover the United Kingdom, Switzerland, Germany and Spain, where the popular Fête de la Musique may be affected.

Forecast and ongoing risk

The anticyclone is expected to keep Italy in its grip at least until the first weekend of July, with daytime highs of 35–37°C common on the Pianura Padana. The health ministry advises avoiding outdoor exposure during the hottest hours. While central regions like Umbria and Molise may see afternoon thunderstorms, the overall picture is one of prolonged, dangerous heat with night-time temperatures offering little respite.