"Air quality has plummeted over much of the Northeast as smoke from wildfires in Canada moves southward. Poor air quality can be dangerous," NOAA's National Weather Service said via Twitter.
The agency warned the population to check the air quality before spending time outdoors, especially people with health problems such as heart ailments, asthma, lung disease, the elderly, and young children.
In cities such as New York, Washington D.C., and Baltimore, "Code Red" alerts have been activated for air quality. According to authorities, 13 states have been affected by poor air quality.
As of Wednesday morning, visibility deteriorated to a rare half-mile in upstate New York, with air quality indexes above 400, while readings above 100 are generally considered unhealthy.
Air quality has plummeted across much of the northeast as smoke from wildfires in Canada moves south. 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. https://t.co/CVx9g8Hm1qpic.twitter.com/aSPUS4LU92
New York officials are urging people to stay indoors, avoid travel if possible, and refrain from any strenuous exercise or activity. Local governments also recommend residents use air purifiers and wear N95 masks if they venture outdoors.
More than 400 wildfires have been raging across Canada for days. Smoke from the provinces of Nova Scotia, Quebec, and Ontario has reached the northeastern U.S. According to the Canadian Ministry of Natural Resources, the fires have consumed 3.3 million hectares of forest so far this year.
The country's Emergency Preparedness Minister, Bill Blair, warned of Canada's plight in what appears to be its worst wildfire season on record. According to Blair, as of June 1, the equivalent of 5 million soccer fields had burned.
The National Weather Service said "No major improvement in air quality is forecast for tomorrow" as smoke plumes continue to move southward from wildfires in eastern Canada.