For weeks, vast areas of Canada have been devastated by mega-wildfires, whose smoke has crossed the Atlantic and reached Europe.

Anyone who has looked up at the sky in recent days will have noticed an unusual phenomenon: a milky veil creating a kind of haze. This time, however, it is not an ordinary meteorological event. The reduced visibility is the result of something happening on the other side of the world: the smoke from the mega-wildfires that have been ravaging Canada for weeks, carried by the winds, has now reached Europe.

Une publication partagée par meteo_vda (@meteovalledaosta)

Hundreds of fires have broken out across the North American nation, forcing several regions to declare a state of emergency. Evacuation orders have been issued for more than 31,000 people, and entire cities remain threatened by the exceptional scale of the blazes. The army has also been deployed to ensure the safety of the population: "This is a difficult time for many Canadians," said Emergency Management Minister Eleanor Olszewski. "This year the fire season started more quickly and more intensely," she added.

All of Canada's central regions are affected by the phenomenon, from the province of Manitoba to British Columbia, Alberta and Saskatchewan. According to the Canadian agency that monitors wildfires, more than 230 fires are currently active, over a hundred of which are still considered "out of control."

Manitoba has issued a state of emergency due to wildfires, prompting the evacuation of approximately 17,000 residents, the largest in recent history. Stay safe 🙏💔 pic.twitter.com/RUVx8K4Xwo

Authorities report that the majority of the fires are human in origin, though not necessarily deliberate: flames often break out accidentally, for example due to high-speed trains passing through extremely arid areas. Lack of rainfall is indeed one of the factors that most contributes to the spread of wildfires, as do exceptional heatwaves. This is why climate change is making such events increasingly frequent and intense.

It is no coincidence that Canadian authorities' forecasts for the fire season are alarming: conditions could be "beyond normal" in June and July, and "well beyond normal" in August — precisely because of dry soils and particularly parched vegetation: the perfect "fuel" for fires.

Some fires have been burning since March, and the flames have already consumed 2.6 million hectares (Canada is still reeling from the summer of 2023, when 15 million hectares burned). That is 143 times the total area of the city of Milan. But beyond the devastation caused by the fires themselves, what is worrying Canadian authorities — and others — is the smoke they generate.

Area burned by wildfires in Canada in 2025 has already SURPASSED the average we typically see in an entire year. We average about 2.1 million hectares per year, but have already eclipsed 2.6 million hectares. And it's only early June. 🇨🇦🔥 pic.twitter.com/TXVbvmfuqZ

Air quality across vast areas of North America is "very poor," with visibility severely reduced. An enormous amount of fine particulate matter is suspended in the air, and conditions are also difficult across the northern United States. The city of Chicago, for example, was enveloped in a dense, murky cloud over the weekend, while Michigan, Wisconsin, Minnesota and Nebraska are also on alert. Both in Canada and the United States, residents have been advised to limit their time outdoors as much as possible.

Wildfires in Canada have forced thousands of residents to evacuate in three provinces, impacting air quality in the U.S. — and smoke from the deadly fires has even blown across the Atlantic and reached the U.K. How many more 'historic' seasons do we need before we #ActOnClimate… pic.twitter.com/DYM1W6BX8t

The arrival of smoke from the Canadian wildfires in Europe, after a journey of thousands of kilometres, was reported as early as 3 June by the Copernicus climate monitoring service. The cloud moves at altitude and, fortunately for that reason, poses no health risks to the population. In this part of the world, the effect is therefore largely visual.

What is concerning, however, are the climatic consequences: "Our data," explained Mark Parrington, scientific director of Copernicus, "show that enormous quantities of greenhouse gases have been dispersed from central Canada's regions over the past few weeks." This only further feeds climate warming, triggering a vicious cycle.