Heat, wind and rain: increasingly extreme weather events
From the 2010-2023 trends based on 3bmeteo data, extreme events are on the rise, the North is affected
by Marta Casadei and Michela Finizio
4' min read
4' min read
Peaks of 300 millimetres of rain in 48 hours caused the overflowing of 21 rivers and widespread flooding in 37 municipalities in the provinces of Forlì-Cesena and Ravenna last May, with damage to the territory amounting to some nine billion euro. The flooding in Emilia Romagna was just one of the extreme weather phenomena of 2023: on 24 July, Syracuse reached a temperature of 47° C, while only a few hours later in Pordenone the largest hailstone ever recorded on the continent fell. On the same night, around 4 a.m., the province of Milan was scourged by winds of over 100 km/h and torrential rain.
Recording the growth of extreme events are the 3bmeteo data processed by the Sole 24 Ore research office: from the analysis of climate surveys in 112 capital cities emerges the moving average of weather indicators by macro-area and its trend from 2010 to 2023. "For scientific findings, more years would be needed. But the 10-year time series already offers numerous indications of the changes taking place in recent years," says Alessandro Conigliaro of 3bmeteo.
Extreme heat
.First of all, over the past thirteen years, rising temperatures have led to an increase in heat waves - which are defined as such when the temperature exceeds 30 degrees for at least three days in a row - and extreme heat peaks, i.e., the exceedances above 35 degrees perceived during summer periods. "The arrival of very sultry subtropical air masses has accentuated these phenomena in the North, where the low ventilation rate increases the perceived temperature and reduces people's climatic comfort," says the 3bmeteo expert.
Last year in the cities of the North there were on average 19 consecutive days over 30 degrees more than in 2010 (6.4 heat waves of three days each), for a total of 47.4 consecutive days of heat: in practice 15.8 waves compared to 9.4 in 2010. Thus, the North is gradually aligning itself with the data of the other regions, where these phenomena were already more frequent: in the Centre, the number of heat waves recorded rose from 15.4 to 19, while in the South the increase was 3.5 events in 13 years.
The increase in temperatures also translates into increasingly marked extreme heat events: there were 17.4 more days on which temperatures reached (or exceeded) 35 degrees in the South, which rose from 3.2 to 20.6 per year; 14 more in the Centre, where they rose from 3.2 to 17.2 episodes; and 11.7 more in the North, where temperatures rose more than in the South as a whole. Here, days of extreme heat in 2010 had been virtually absent, a total of just 0.2 days on average in northern cities.
