Autumn heatwaves: a concerning WEATHER phenomenon, especially in November
This trend, which manifests with temperatures well above the seasonal average, is the result of various interconnected climatic factors, and scientists increasingly link it to global climate change. If in the past November temperatures marked the beginning of winter, with a significant drop in degrees and a harsher climate, today November often brings days similar to those of autumn or even late summer, causing perplexity and concern. The origin of abnormal heat waves in Italy and other parts of Europe can be traced back to the increased frequency of particular atmospheric configurations. One of the main factors is the African anticyclone, a high-pressure system that expands from North Africa towards southern Europe. This phenomenon was previously typical of the summer season, bringing intense heat waves especially in July and August.
However, in recent years, there has been an increased frequency and intensity of African anticyclones even in autumn and even in winter.
The presence of these warm air masses prevents the entry of colder currents from the north, thus retaining heat in Europe and creating more extended and lasting “St.
Martin’s summer” situations compared to the past. One of the most striking examples occurred in November 2022, when several Italian cities recorded temperatures well above the seasonal average.
In cities like Rome, Florence, and Milan, peaks of 22-24 degrees were recorded, temperatures decidedly uncommon for the period. The same happened in southern areas, with cities like Naples and Palermo recording peaks close to 30 degrees, heat levels usually observed at the beginning of September. This phenomenon was accompanied by clear skies and sunny days, situations that help maintain high temperatures even at night.
In November 2019, there was also an abnormal heat wave, with temperatures over 4-5 degrees above the seasonal averages in many parts of the country. The increase in temperatures in November is not an isolated phenomenon, but rather part of a broader picture of global warming.
Data confirm that in recent decades the Earth’s average temperature has increased by about 1.1 degrees Celsius compared to pre-industrial levels, and Europe is one of the fastest-warming continents. This warming is responsible for significant changes in seasonal climatic patterns, as demonstrated by heat waves occurring in periods of the year when cooler or cold temperatures were usually recorded.
In this context, the Mediterranean serves as a ”hot spot” for climate change, with warming above the global average and an increase in the frequency of extreme events. Abnormal heat waves in November not only cause climate-related discomfort but also have consequences for the environment and the economy. Crops and natural ecosystems are affected by this out-of-season warming, as many plants and animal species regulate their biological cycles based on temperature. Plants, for example, might sprout out of season or be induced to early flowering, only to suffer damage in case of sudden temperature drops. Animals that hibernate or migrate based on seasonal variations can be disoriented, affecting biodiversity and the natural balance of species. Tourism is also affected, as the demand for winter activities like skiing and mountain sports is compromised by milder winters.
Ski resorts, especially those at lower altitudes, might see a reduced ski season duration or even the impossibility of operating without the massive use of artificial snow, with significant economic repercussions. An example was the winter of 2022-2023, which saw a severe lack of snow in the Alps already in the early months of the season, leading many resorts to delay opening or reduce activities.
The need to invest in expensive technologies for artificial snow production is not sustainable for all resorts, and many mountain sectors are struggling to cope with these changes. The abnormal heat waves occurring in November in Italy are part of a broader phenomenon linked to global climate change.
This out-of-season warming, besides being a symptom of a transforming planet, invites us to reflect on the urgency of adopting more sustainable environmental policies to limit further temperature increases. Scientific evidence and episodes of recent years make it increasingly clear how necessary it is to intervene promptly to prevent climate changes from becoming irreversible, and for November’s abnormal heat to become the norm rather than the exception.
However, in recent years, there has been an increased frequency and intensity of African anticyclones even in autumn and even in winter.
The presence of these warm air masses prevents the entry of colder currents from the north, thus retaining heat in Europe and creating more extended and lasting “St.
Martin’s summer” situations compared to the past. One of the most striking examples occurred in November 2022, when several Italian cities recorded temperatures well above the seasonal average.
In cities like Rome, Florence, and Milan, peaks of 22-24 degrees were recorded, temperatures decidedly uncommon for the period. The same happened in southern areas, with cities like Naples and Palermo recording peaks close to 30 degrees, heat levels usually observed at the beginning of September. This phenomenon was accompanied by clear skies and sunny days, situations that help maintain high temperatures even at night.
In November 2019, there was also an abnormal heat wave, with temperatures over 4-5 degrees above the seasonal averages in many parts of the country. The increase in temperatures in November is not an isolated phenomenon, but rather part of a broader picture of global warming.
Data confirm that in recent decades the Earth’s average temperature has increased by about 1.1 degrees Celsius compared to pre-industrial levels, and Europe is one of the fastest-warming continents. This warming is responsible for significant changes in seasonal climatic patterns, as demonstrated by heat waves occurring in periods of the year when cooler or cold temperatures were usually recorded.
In this context, the Mediterranean serves as a ”hot spot” for climate change, with warming above the global average and an increase in the frequency of extreme events. Abnormal heat waves in November not only cause climate-related discomfort but also have consequences for the environment and the economy. Crops and natural ecosystems are affected by this out-of-season warming, as many plants and animal species regulate their biological cycles based on temperature. Plants, for example, might sprout out of season or be induced to early flowering, only to suffer damage in case of sudden temperature drops. Animals that hibernate or migrate based on seasonal variations can be disoriented, affecting biodiversity and the natural balance of species. Tourism is also affected, as the demand for winter activities like skiing and mountain sports is compromised by milder winters.
Ski resorts, especially those at lower altitudes, might see a reduced ski season duration or even the impossibility of operating without the massive use of artificial snow, with significant economic repercussions. An example was the winter of 2022-2023, which saw a severe lack of snow in the Alps already in the early months of the season, leading many resorts to delay opening or reduce activities.
The need to invest in expensive technologies for artificial snow production is not sustainable for all resorts, and many mountain sectors are struggling to cope with these changes. The abnormal heat waves occurring in November in Italy are part of a broader phenomenon linked to global climate change.
This out-of-season warming, besides being a symptom of a transforming planet, invites us to reflect on the urgency of adopting more sustainable environmental policies to limit further temperature increases. Scientific evidence and episodes of recent years make it increasingly clear how necessary it is to intervene promptly to prevent climate changes from becoming irreversible, and for November’s abnormal heat to become the norm rather than the exception.
