Nearly 90 million people in the US are facing unhealthy air quality warnings — while 18 million acres of wildfires in Canada are burning and sending smoke across the states.
Canada has recorded its worst fire season with hundreds of wildfires currently raging across the country.
Smoke has once again entered the US and has now triggered air alerts for the entire states of Iowa, Wisconsin, Illinois, Indiana, Michigan, Delaware and Maryland.
Parts of Kansas, Missouri, Minnesota, Ohio, Pennsylvania, New York and Virginia are also on alert, with residents advised to stay indoors as much as possible.
Yesterday, New York Governor Kathy Hochul and New York Mayor Eric Adams both warned that the smoke that blanketed the city earlier this month will return.
Haze from Canadian wildfires covers the skyline of downtown Pittsburgh as seen from West End Overlook in Elliott
The typical Pittsburgh skyline is completely obscured by the wall of smoke that has descended from Canada
Haze from Canadian wildfires covers the Chicago skyline as seen from the city’s South Loop neighborhood
A freighter passes through the Detroit River as smoke fills the air, reducing visibility of Windsor, Ontario earlier in the day
People in Chicago have resorted to wearing masks as smoke from the wildfires filters into the city
Chicago had also recorded the worst air quality in the world yesterday as it was also consumed by smoke from the fires.
A measurement recorded Tuesday by the World Air Quality Index ranked Chicago as the worst quality in the world.
The city was flagged as Unsanitary Air with a reading of 175 AQI, with parts of Michigan reaching higher.
The index is a measure of five common pollutants and runs on a scale of 0 to 500, with a score over 150 considered ‘unhealthy’.
It has since been kicked off from the top spot by Dubai in the United Arab Emirates and ranks third behind Detroit.
According to the index, Washington DC, Minneapolis, Chicago and Detroit all rank in the top ten for the worst air quality in the world.
Advice from Air Now is urging people to stay indoors and reduce activity levels due to the air outside.
The New York City Health Department is urging people to take precautions as the smoke is expected to have a “significant impact” on air quality and warned it could reach dangerous levels.
Firefighters battle fires in northern Quebec on Sunday as more than 480 fires burn across the country
Four cities in the United States that are close enough currently make up the majority of the world’s ten worst places for air quality
The above map from AirNow shows which states have the most effect from smoke, with a high concentration around the Midwest
This map provided by AirNow shows how far the smoke from Canada could have traveled
Video shared on social media Tuesday shows downtown Chicago under smoke, with a thick haze visible around the area.
According to current figures from the Canadian Interagency Forest Fire Center, there are currently 483 active fires in the country.
252 of these are classified as out of control, with 155 under control and a further 76 in detention.
Smoke from the fires also crossed the Atlantic and reached Western Europe earlier this week.
The smog that has made its way to Europe has done so via the jet stream – high winds in the upper layers of the atmosphere.
This means that the smoke will not lead to dramatically worse surface air quality, as it did in the northeastern US a few weeks ago.
Smoke rises from internal hot spots blazing at the Kimiwan wildfire complex in Northern Sunrise County, Alberta, Canada
The Met Office said the smoke would not have the same effect as in the northeastern US because it is too high in the atmosphere.
Earlier this month, New York City was shrouded in a thick orange fog after haze and smoke from the wildfires shrouded the Manhattan skyline
The UK Met Office said that although the smoke is high in the atmosphere, it could make for some vibrant sunrises and sunsets.
Earlier this month, the northeastern United States was blanketed in smoke from the fires that placed 100 million people under an air quality alert.
At the time, health experts warned that inhaling the mist could be as harmful as smoking 22 cigarettes a day.
Nanoparticles from the smog are so small that they can enter the lungs and bloodstream, causing side effects such as eye and throat irritation and difficulty breathing.
A cloud of smoke from the wildfires descended on New York, preventing those in Manhattan from seeing the New Jersey skyline across the Hudson River.
According to the National Weather Service, not only were New Yorkers sent indoors, but air quality warnings were also introduced in states such as Massachusetts, New Hampshire, Pennsylvania, Maryland, Illinois, Virginia and the Carolinas.
Conditions in Chicago are expected to continue overnight, but should slowly push south and abate, according to the National Weather Service.