Canadian wildfire smoke worsens air quality across the Northeast and Mid-Atlantic

Smoke from more than 180 wildfires burning in Canada pushed a thick haze into the Northeast and Mid-Atlantic, worsening air quality in major population centers and forcing residents to cut back outdoor plans as forecasters expect the plume to linger through Friday. AirNow had a system alert titled Wildfire Smoke in Multiple States. Its Fire and Smoke map showed local impacts.

The heaviest exposure fell across the corridor that includes New York City, Philadelphia, Washington, Boston and parts of New England, where air quality alerts spread across at least 17 states in one recent outbreak and conditions were already poor in Massachusetts. New York City Emergency Management extended its heat emergency plan into Thursday as Canadian wildfire smoke moved into the region, kept cooling centers open, and offered free KN95 masks.

Wildfire smoke can push the Air Quality Index into unhealthy, very unhealthy and hazardous ranges, and the risk becomes more serious for people with asthma, heart disease and other respiratory conditions. A New York City reading of 405 AQI during a past smoke episode put the city in the hazardous range.

New plumes arrived from Canada and added to a pattern that has repeated across recent summers. On June 7, 2023, the EPA issued a Canadian Wildfires Prompt Poor Air Quality Alert for Parts of New England, and NOAA’s National Environmental Satellite, Data, and Information Service tracked historic levels of harmful smoke affecting millions in the eastern United States. During a June 2023 smoke event, more than a third of the U.S. population fell under air-quality alerts.

School schedules, flights and outdoor work have all taken hits during heavy smoke episodes, especially where haze lingers over metro areas and visibility drops. The national Air Quality Forecast system, run by EPA and NOAA, warns the public as Canadian smoke rides south and east.