More than 800 wildfires are currently raging across Canada, sending extensive plumes of smoke southwards into the United States and prompting severe air quality warnings. As of Thursday, 858 fires were actively burning, with 30 new blazes igniting that day alone, according to the Canadian Wildland Fire Information System. A significant number of these fires are reported to be burning out of control, presenting a substantial challenge to firefighting efforts.
The smoke has led to air quality alerts spanning the US Upper Midwest, the Great Lakes region, and into the Northeast. Authorities in Michigan and Minnesota have deemed air quality in large parts of these states as "hazardous," advising residents to remain indoors. Cities such as Detroit, Minneapolis, Chicago, and Toronto have registered some of the worst air quality levels globally, according to Swiss air quality tracker IQAir. In New York State, air quality was considered "very unhealthy" in western regions and "unhealthy" in the New York City metro area on Thursday, leading to the activation of air quality emergency protocols, including the provision of cooling centres and KN95 masks.
The primary source of the smoke affecting these regions stems from a large cluster of fires in northwestern Ontario. These fires are responsible for the thick smoke over Thunder Bay and Toronto, with higher altitude smoke drifting over the Great Lakes and New York, creating hazy skies and intensifying sunrise and sunset colours. Northwesterly winds are forecast to continue directing this smoke into northern US states for the remainder of this week and into the upcoming weekend, raising concerns about potential impacts on areas like New Jersey, which is due to host the World Cup final on Sunday. A shift in wind direction anticipated by Monday could steer the smoke towards Quebec, potentially improving air quality further south in the US.
The recurring nature and intensity of these wildfires have drawn criticism from US lawmakers. Republican representatives from Michigan have penned an open letter to Canadian Prime Minister Mark Carney, expressing frustration over what they describe as a lack of improvement in wildfire management for the third consecutive year. Prime Minister Carney, in response, emphasised the shared responsibility of both nations in combating climate change and stated his government is in close communication with affected provinces and communities. Ontario Premier Doug Ford also defended his government's handling of the fires, noting that over 150 fire crews are actively engaged in battling the blazes.
Experts attribute the increased frequency of wildfires, particularly since 2015, to extreme climate warming and atmospheric drying. Professor Laura Chasmer from the University of Western Ontario explained that while fires historically occurred more often in western Canada, recent years have seen this trend shift eastward to Ontario, Quebec, and the Atlantic provinces. This geographical shift has resulted in more noticeable smoke impacting densely populated urban centres like Toronto and New York, further straining Canadian firefighting resources, which primarily focus on preventing the spread of flames to nearby communities.