What to know about Canada’s exceptional fire season

Canada is burning.

That, at least, is the perception around the world as hundreds of wildfires have ravaged the country, displaced tens of thousands of people and raised a global alarm about the dangers of climate change.

In a nation famed for its orderliness, out-of-control wildfires have created an ominous feeling of a country under siege, spreading from west to east coasts and sending toxic plumes over major cities like Ottawa, the capital, Toronto, the largest city and financial capital, and Montreal.

As smoke billowed across the United States, disrupting life in the Northeast and turning the New York City skyline an apocalyptic orange hue, the wildfires also underscored how environmental disasters don’t obey borders.

Here’s what you need to know about wildfires and wildfire season in Canada.

While bushfires are common in spring and summer across much of Canada, they usually burn in remote, sparsely populated areas. But this year’s fires have already been substantial: hundreds are burning across much of the country.

A dry, windy and abnormally hot spring created ideal fire conditions in many regions with the first major wildfires erupting in May in Alberta, an oil and gas producing province that is regularly plagued by wildfires.

So far, more than 2,300 fires have consumed about 9,142,899 acres of forest, far more than the 674,357 acres that burn, on average, at this point in the season.

Canadian government forecasts show the whole country a an above-average risk for forest fires for the rest of June. Ontario and British Columbia have seen relatively limited fire activity, but most experts predict it won’t last. But not all parts of the country will be affected; arctic regions above the tree line are too cold for trees.

The distribution of the major fires is also unusual: from Alberta in the west to Nova Scotia on the Atlantic coast, three time zones apart. The smoke that has plagued the United States comes mostly from areas of Quebec not normally associated with major fires.

Lightning typically causes about half of the wildfires in Canada each season. These fires are generally the most damaging because they tend to occur in remote areas and are difficult for firefighters to access. They account for about 85% of the forest that is burned in most seasons.

Humans are responsible for the other half of fires not caused by lightning, starting them in various ways, usually inadvertently through negligence. One of Alberta’s fires this year started when an all-terrain vehicle caught fire. Some provinces have closed parks and forests to people and banned camping and all open fires to limit the risks.

In years past, sparks from braking trains as they descended mountain passes also caused fires.

Climate research suggests that the heat and drought associated with global warming are the main reasons for the increase in larger wildfires.

Canada has the largest intact forest ecosystem in the world, and many parts of the country have recently experienced drought and intense heat. This can make trees vulnerable to fire, and can dry out dead grass, pine needles, and any other material at the bottom of the forest floor that can serve as firewood when a fire rages through a forest.

Wildfire experts see signs of climate change in drought, intense heat and longer fire seasons that have made these wildfires more extreme and likely will in the future.

Smoke patterns, like fires themselves, depend on weather conditions. In cities that have spent days dealing with smoke and ashen skies, help is on the way.

Rain and cloud cover near the fires in Ontario are expected to improve air quality in Toronto.

Steven Flisfeder, a warning preparedness meteorologist at Environment and Climate Change Canada, said the weekend could improve air quality in Toronto, thanks to rain and cloud cover near wildfire areas in Ontario.

Catherine Brabant, a meteorologist at Environment Canada, said it doesn’t look like wind patterns will move smoke plumes towards Quebec’s largest city, Montreal.

But with wildfires growing in frequency and intensity, experts say smoke seeping into the US could become more common.

Canada does not have a national firefighting force but relies on its 10 provinces and three territories.

In normal times a coordination center moves firefighters and equipment such as water bombers and helicopters from provinces with few fires to fire-ravaged crisis areas.

These, however, are not normal times.

The scale and scope of this year’s fires are making it difficult for provinces to share firefighters and equipment, and the system is stretched to its limits.

To ease the tension, more than 1,100 firefighters traveled to Canada from abroad, including groups from France, Chile, Costa Rica, the United States, Australia, New Zealand and South Africa.

Vjosa Isai contributed to the report.