Climate Italy
In Northern Italy, the climate varies according to altitude and exposure. It is generally continental, humid with hot summers. The marked differences in temperature between the seasons are due to the differences in latitude, the Alpine, Mediterranean and humid subtropical influences (north and east). The region enjoys a rather temperate climate, with contrasting seasons at high altitudes, from -5°C in winter to 25-30°C in summer, and a rather abundant snowfall each winter on the massifs. The hot summer periods are accompanied by a certain mugginess in the Po Valley, in Veneto, while the Adriatic, Ligurian and Tyrrhenian coasts enjoy milder temperatures thanks to the proximity of the sea, from 1°C in winter to 30°C in summer, the air becoming very dry inland in Tuscany, which is then marked by heavy autumn rains. In short, it is a variable temperate weather, which also suffers the effects of global climate change.
Panorama of the climate in northern Italy
The climate of the Italian Alps has historically been characterized by severe cold and heavy snowfall in winter. Let's mention in general the main characteristics of the Italian climate, hoping that the current serious disturbances in the mountains and in the plains do not become the norm. In the Italian pre-Alpine regions, relatively mild temperatures in summer are followed by rainfall, sometimes torrential, at the end of September/beginning of October, but still enjoy a favorable Mediterranean regime, in a temperate, cool semi-continental climate, without extremes of heat, cold or aridity. Thus, in the region of the Great Lakes (Maggiore, Garda, Como...), these vast expanses of water, although of glacial origin, rarely see their temperatures drop below zero.
The typical Alpine climate of Valle d'Aosta is characterized by cool summers and cold winters. In the steep regions of the Aosta Valley and Piedmont, in the central valley of the Dora Baltea River, the climatic conditions are even harsher, with heavy winter snowfalls and little precipitation the rest of the year. In fact, the mountain people have always had to dig large canals(Rûs) to bring water from the glaciers, a method of irrigation still used today.
Wet continental to hot summer in town
In Turin, the climate is often subject to heavy rainfall in May (123 mm / 12 days) and November (118 mm / 8 days). This region of Piedmont, with its proximity to the Alps, is also subject to strong, dry and hot winds (this is called the foehn effect, which is the meeting of the atmospheric circulation and the relief when a prevailing wind meets a mountain range).
Also continental, Milan's climate alternates between hot, humid summers and moderately cold (but not as cold as in Turin, for example) and potentially snowy winters. Fog(nebbia) is often present in winter, especially in the south of the city. The arrival of spring is therefore a blessing! Thanks to the barrier of the Alps, a real natural wall against the North Atlantic currents, the flowering season comes earlier than north of the Alps. The fairly abundant rainfall is distributed throughout the year with summer thunderstorms and autumn rainy episodes. As in all large metropolises, the center of Milan is warmer than the Lombardy countryside. It is particularly affected by an urban heat island. This is due to several factors: the high population density, the low amount of sunlight reflected from the land surface and the lack of ventilation. Temperature differences of more than 6°C between the city center and the immediate countryside have been observed.
Humid subtropical in the north, east and the Po Valley
The Po Valley, with its continental climate, sometimes experiences very cold winters. It is said that Piacenza experiences the same winter temperatures as Berlin! However, the Po Valley is characterized by a particular climate: the absence of a dry summer season. During the summer months, a quarter of Italy's annual precipitation normally falls, while Naples and Campania receive only 10% of the total precipitation in summer. Thanks to the waters of the Po and the humid climate, the vegetation is particularly green.
In Veneto, the same humid continental climate with hot summers is evident in the cold winters, with frost, sometimes thin layers of snow and always that morning mist, so romantic on the lagoon. Summers are hot and humid. Precipitation is minimal in the winter, but in the summer it falls in the form of thunderstorms, sometimes violent, which break out after a hot and humid day, and in the fall in the form of continuous rain.
In Venice, since the MOSE system is active (October 2020), the winter floods, which locals call theAqua Alta, are less catastrophic. Immersed in the waters of the lagoon, this enormous machinery is activated when tides of more than 110 cm are expected. The metal dikes are deployed in the sea and prevent the rise of water in the city. Part of St. Mark's Square may be submerged, but traffic is not hindered as it was before the MOSE dikes were put into operation.
On the Adriatic or Tyrrhenian side, it is always the Mediterranean with its mild climate and good sunshine. Going up the Adriatic coast to the Gulf of Trieste, average temperatures are around 15°C. In winter, temperatures rarely fall below freezing and bad weather (snow, fog, hail) is not frequent. With an average annual humidity of 64%, one of the lowest in Italy, rainfall is rare in Trieste and is most often manifested in thunderstorms. During the summer months, temperatures rise from 25 to 30°C.
The exception to this generally mild Trieste climate are the bora days. And when the bora blows, it is: "All to the shelters!" This cold and violent wind is of continental origin from the east-northeast. As it penetrates the valleys, it warms up by 3 to 4°C and reaches the Gulf of Trieste in extremely violent gusts that can reach 180-200 km/h, leaving an unstoppable sensation of winter cold on the skin. In summer, in exceptional cases, the bora gusts gain additional speed at the mouth of the Adriatic, reaching in high seas more than 50 knots. Of course, the boats then remain at the quay... It is in this Italian region that the bora is the strongest and most frequent. Only the coastal area, from Miramare to Sistiana, escapes it.
On the back plateau of Trieste, from 200 to 500 m of altitude, the villages and the localities of the Triestine Karst suffer the influence of the relief. The climate is much more continental and often brings cold nights with negative minimum temperatures. In Basovizza, for example, near the Slovenian border (370 m), the average annual temperature is about 11 °C, with an average in winter around 1.5 °C and in summer around 20.6 °C.
On the other side of the boot, all along the Ligurian coast, the climate around Genoa and the Cinque Terre is pleasant with mild winters, rare snowfalls, exceptional frosts, hot summers without being scorching and a higher humidity level than elsewhere on the Mediterranean coast: a climate that suits perfectly the lush vegetation of the Riviera dei Fiori around San Remo.
In the Tuscan interior, influenced by the Tyrrhenian Sea, the climate is Mediterranean, becoming increasingly continental and dry, even arid in the center of the region. Also marked by the continental nature of the Apennines and the Tuscan hills, Emilia-Romagna is crisscrossed by rivers that flow directly into the Adriatic Sea, ensuring a certain humidity even in summer. Winter is cooler than on the coast.
Risks related to climate change
In recent decades, the climatic hazards in Northern Italy, combined with the increase in average temperature and the change in precipitation patterns, have caused extreme weather phenomena. Heavy rains are often the cause of human and material tragedies. In Genoa, the flash floods and mudslides of November 2011 are still remembered. Ditto for the collapse of the Morandi Bridge after heavy rains in August 2018, the historic floods with more than 60 cm of water locally, the landslides in Piedmont, Valle d'Aosta and Liguria in October 2020, the deluge in Senigallia between Bologna and Ancona in October 2022, the list is long... Italy is considered, not least because of these disasters, one of the European countries most exposed to the risks related to climate change.
Heat waves and drought are also causes of natural disasters. The melting of glaciers has become irreversible, as was seen on July 4, 2022, when a huge block broke off from the Marmolada glacier, the highest peak in the Dolomites, killing six people and injuring eight. The day after a record temperature was reached at the summit (10°C), the glacier broke away from the wall, near the Punta Rocca area, along the route normally used by climbers. The largest glacier in the Dolomites is no longer eternal. It has already lost 30% of its snow cover in the last ten years. According to Italian experts, new ice collapses are to be feared and glaciologists estimate that it will simply disappear before 2042. If the climate is changing at the global level, pollution from regional industries is also causing temperatures to rise over time and increasing the greenhouse effect. Temperatures above 20°C at 2,000 m altitude and a barometer that no longer falls below zero inevitably lead to the formation of water pockets under the ice, causing these huge blocks to slide.
Water resources are also impacted by climate change; they are under pressure, agriculture is directly impacted. Drought is also looming in northern and central Italy. In the summer of 2022, the most fertile regions of Italy experienced a historic drought. In the Po plain, farmers saw their rice and grain fields burn in the sun while the river was at its lowest level in 70 years. Heat spikes and thunderstorms, which turn into tornadoes or hailstorms damaging the rest of the crops still standing, are the cause.
Another devastating effect is the erosion of the coastline, a major risk of flooding for Venice and other coastal cities on the Adriatic coast.
