Millions are being urged to stay indoors as thick wildfire smoke blankets parts of the Northeast and Midwest, sending air quality to dangerous levels.
Air quality alerts have been issued across Connecticut, Illinois, Indiana, Michigan, New Jersey, New York and Wisconsin as smoke from massive Canadian wildfires drifts south.
Officials have warned that wildfire smoke contains fine particulate matter, also known as PM2.5, which consists of microscopic particles of toxic compounds, small enough to penetrate human tissue and cause breathing issues.
Some areas are expected to experience air quality ranging from Unhealthy for Sensitive Groups to Very Unhealthy, with forecasters warning that conditions could briefly reach the EPA’s highest Hazardous category.
Most of the air quality alerts remain in effect until midnight Wednesday, while Michigan and Wisconsin are expected to face dangerous wildfire smoke through Thursday.
Health officials are urging residents to limit time outdoors, avoid strenuous exercise and keep windows closed wherever possible. People with asthma, heart disease, other respiratory conditions, older adults and young children are considered most at risk.
Several states have also advised residents to run air conditioning systems with high-efficiency filters and watch for symptoms including coughing, wheezing, chest tightness and burning eyes.
The alerts come as smoke from hundreds of active Canadian wildfires continues to spread across large swaths of the US.
Michigan is experiencing the worst of the wildfire smoke, leaving drivers unable to see
Air quality alerts have been issued across Connecticut, Illinois, Indiana, Michigan, New Jersey , New York and Wisconsin as smoke from massive Canadian wildfires drifts south.
More than 800 active wildfires have been burning across Canada this summer, particularly in the Northwest Territories, Saskatchewan, Manitoba, Ontario and Quebec.
AccuWeather Expert Meteorologist Brandon Buckingham said in a statement: ‘Smoke conditions are expected to get worse this evening and through Thursday across parts of southern New England, most of New York State, including the NYC area, then down into Pennsylvania and New Jersey.
‘It will also be quite smoky across much of lower Michigan and into northern Ohio.’
The AccuWeather Air Quality Scale forecasts ‘Dangerous’ air conditions in Rochester and Buffalo, ‘Very Unhealthy’ conditions on Wednesday in Boston and ‘Unhealthy’ conditions in New York City and Detroit.
New York City Mayor Zohran Mamdani said on X: ‘Air quality has reached unhealthy levels in parts of NYC due to smoke from Canadian wildfires moving through the city.
‘Poor air quality affects everyone, but some people are more sensitive to it than others, including people with heart or lung conditions, older adults, pregnant New Yorkers, and infants and children.
‘Avoid unnecessary outdoor activities [and] head to a cool space indoors with AC if possible.’
PM2.5 is considered one of the most dangerous forms of air pollution because the microscopic particles are small enough to bypass the body’s natural defenses and lodge deep inside the lungs.
Buffalo, New York is experiencing orange skies from the wildfire smoke that is expected to linger until at least Thursday
Exposure can trigger coughing, wheezing, shortness of breath, chest tightness and irritated eyes, nose and throat, while prolonged exposure has been linked to more serious cardiovascular and respiratory problems.
The Michigan Department of Environment, Great Lakes and Energy (EGLE) issued a statewide Air Quality Alert through Thursday, warning that fine particulate pollution from Canadian wildfire smoke is expected to range from Unhealthy for Sensitive Groups in southern parts of the state to Unhealthy farther north.
Officials warned that hourly concentrations could at times climb into the Very Unhealthy and even Hazardous range, particularly across northern Michigan.
Smoke plumes have already reached the Upper Peninsula and northern Lower Peninsula and are forecast to continue drifting south toward the Michigan-Indiana border.
Residents, especially those with asthma or heart disease, have been advised to avoid strenuous outdoor activities whenever possible.
Households are encouraged to keep windows closed overnight and use central air conditioning equipped with MERV-13 or higher-rated filters.
The Wisconsin Department of Natural Resources warned that 24-hour air quality could reach Very Unhealthy levels, while short-term conditions may briefly climb into the Hazardous category, the most serious level on the Air Quality Index.
Sensitive groups have been told to avoid all outdoor physical activity during periods of very unhealthy air, while everyone else has been urged to shorten outdoor activities and move indoors if symptoms develop.
Meteorologists are sharing images of Buffalo, showing brown skies from the smoke traveling into the US from Canada
The advisory is expected to remain in effect through at least Thursday and could be extended depending on smoke conditions.
New York is also under an Air Quality Alert as elevated levels of fine particulate pollution move across the state.
The New York State Department of Health recommends limiting strenuous outdoor physical activity, particularly for children, older adults and anyone with existing respiratory or heart conditions.
Anyone experiencing symptoms has been advised to consult their physician.
In neighboring Connecticut, air quality alerts have also been issued as wildfire smoke continues moving into the region, prompting officials to warn residents about elevated fine particle pollution and the increased risk of respiratory problems for vulnerable people.
Illinois and Indiana are also being affected as smoke continues pushing south across the Great Lakes.
Air quality officials warned that fine particulate pollution could create unhealthy conditions, particularly for sensitive groups, and encouraged residents to reduce prolonged outdoor activity until the smoke clears.
New Jersey has declared a Code Orange Air Quality Action Day covering parts of the state. This level is officially classified as Unhealthy for Sensitive.
The New Jersey Department of Environmental Protection said concentrations of ground-level ozone and fine particulates are expected to become unhealthy for sensitive groups, including children, older adults and people with asthma, heart disease or other lung conditions.
Officials advised residents to avoid strenuous outdoor exercise until air quality improves.
