Wildfire season 2023: Tens of millions under air quality advisory from Canadian wildfire smoke

Smoke from Canada's wildfires has again covered large  of the US, leaving tens of millions of Americans under air quality advisories.

Canada has seen its worst wildfire season on record this summer, and air quality conditions in parts of North America have experienced historic unhealthy levels since June.

Wildfires have reportedly burned over 24 million acres (10 million hectares) in Canada so far this year. That is equivalent of an area about the size of Iceland or the US state of Indiana.

Although both the provinces of Quebec and Ontario lifted their fire bans on Monday, out of control wildfires in the Northwest Territories, Alberta and British Columbia provinces continue to make air quality bad for tens of millions of people. 

Health officials are now warning for medium to high smoke risk in cities across Canada, including Calgary, Montreal, Quebec City and Toronto, according to the CBC. 

According to the New York Times, this week air quality alerts were issued for several US states from Montana to the Dakotas. Also other states were included like Nebraska, Alabama,Tennessee, Ohio, North Carolina and other states along the northeastern part of the US.  

US regions with an AQI over 150 on Tuesday afternoon included parts of Georgia, Tennessee, North Carolina, South Carolina, Vermont and New Hampshire, according to AirNow, which tracks airborne pollutants.

Nearly 900 fires are burning across Canada, with 590 out of control, according to the Canadian Interagency Forest Fire Centre.

Illustration above: A map of data from air sensors across the world show air particle levels. Deep purple dots in northern Canada show where N.W.T. communities are experiencing significantly worse air quality than other communities in Canada, the U.S. and the world. (PurpleAir)