Wildfire Smoke Triggering ‘Dangerous’ and ‘Very Unhealthy’ Air Quality Across Great Lakes, Northeast

Wildfire smoke blowing across the Great Lakes and into the Northeast is creating significant air quality concerns in major cities like Toronto, New York, and Boston as smoke mixes with high heat, pollution and humidity. In some areas, the smoke can be very thick, causing air quality to be hazardous.

• AccuWeather expert meteorologists are forecasting hazy conditions across many major U.S. cities including Philadelphia, Cleveland, Chicago, Detroit, and Washington, D.C.
• More significant impacts are expected across Toronto and southern Canada, Wisconsin, Michigan, far eastern Minnesota, much of New York including New York City, and New England

Wildfire smoke isn’t the only thing driving poor air quality in the East, ozone is a factor too, especially in bigger cities. Car and factory emissions combine with sunshine and dry weather to raise ozone levels, and that ozone pollution is now mixing with wildfire smoke and humidity. It’s a compounding effect,” said AccuWeather Expert Meteorologist Elizabeth Danco.

“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,” said AccuWeather Expert Meteorologist Brandon Buckingham.

The AccuWeather Air Quality Scale forecasts ‘Dangerous’ air conditions in Rochester and Buffalo, ‘Very Unhealthy’ conditions Wednesday in Boston, Toronto, and ‘Unhealthy’ conditions in New York City and Detroit.

In 2023, a major fire outbreak in Quebec caused days of unhealthy air quality in the northeastern U.S. This current event could cause similar levels of poor air quality in spots.

After Thursday, smoke could linger in parts of the Northeast, Ohio Valley and mid-Atlantic into Saturday although it may not be as thick as Wednesday and Thursday.

AccuWeather Air Quality Scale
The AccuWeather Air Quality Scale uses six color-coded categories tied to pollutant exposure thresholds, helping people make better clean-air decisions by showing how long it is generally safe to be outdoors at each level of air pollution.

Tips for Navigating Poor Air Quality

• Review Air Quality Index before heading outside, especially during the morning and evening when smoke can settle closer to the ground
• Children, older adults and people with asthma, COPD or heart disease may need to limit time outdoors when air quality reaches unhealthy levels
• Strenuous outdoor activity, including sports practices, running, yard work and outdoor labor, may be more difficult or risky during smoky conditions
• Keeping windows and doors closed, running air conditioning on recirculate and using an air purifier, if available, can help reduce indoor smoke exposure
• A well-fitting N95 or KN95 mask can help reduce exposure for people who need to spend time outdoors in smoky conditions

Tracking the Smoke

The smoke cascading into the U.S. comes from wildfires in southern Ontario, near the border of Canada and Minnesota. The wildfire smoke is expected to spread across parts of the Great Lakes and Northeast through at least Thursday with thick smoke spreading into the U.S. at times.