Maps, Satellite Images Show Canadian Wildfire Smoke Enveloping U.S. East Coast As Air Quality Deteriorates

Smoke from wildfires in Canada is affecting the air quality in parts of the Northeast, environmental officials said, and maps and satellite images are showing the large-scale impact of the blazes.

An air quality health advisory was in effect Wednesday for much of New York, according to the state's Department of Environmental Conservation. The advisory showed air quality was "unhealthy" for the New York City metropolitan area, Eastern Lake Ontario and Central New York. It said air quality was "unhealthy for sensitive groups" in Long Island, the Lower Hudson Valley, Upper Hudson Valley and Western New York. Air quality in the Adirondacks was "moderate," according to the advisory.

A similar health advisory had been in effect on Tuesday, when the air quality for the New York City metro area, Lower Hudson Valley, Upper Hudson Valley, Adirondacks, Eastern Lake Ontario, and Central Regions was classified as "unhealthy for sensitive groups."

By Tuesday night, the air quality for the New York City metro area was considered "Very Unhealthy." New York City Mayor Eric Adams said in a statement that the air quality was expected to improve slightly overnight and into Wednesday morning, but deteriorate again Wednesday afternoon and evening. Satellite images captured around that time show thick smoke blanketing New York and much of the Northeast.

Adams said New Yorkers should limit outdoor activity Wednesday while noting that children, older adults and those with heart or breathing problems may be "especially sensitive and should avoid outdoor activities during this time."

The Air Quality Index (AQI) measures the level of fine particle pollution in the air, which includes a mixture of solids and liquid droplets, according to officials. 

The dip in air quality comes as more than 100 wildfires continue to burn across the Canadian border in Quebec and Ottawa. Strong winds will help direct heavy smoke through the Northeast until at least Wednesday, according to the National Weather Service. 

"Raging wildfires in Quebec are generating large smoke plumes to the north and ALL of the smoke is being funneled right into the Northeast," NWS Mount Holly tweeted. "Unfortunately, more smoke is on the way for tonight and Wednesday."

The National Weather Service advised people in the Northeast to monitor their local air quality forecasts before spending time outdoors. 

"Air quality has plummeted across much of the northeast as smoke from wildfires in Canada moves south," NWS tweeted. "Poor air quality can be hazardous. Before spending time outdoors, check the air quality forecast. Make sure you aren't doing yourself more harm than good."

Air quality warnings are also in effect in Maryland, St. Louis, Philadelphia and Delaware.