Canada is battling more than 700 active wildfires across the country, roughly two-thirds of which are burning out of control, according to the Canadian Interagency Forest Fire Center (CIFFC). Smoke billowing from the blazes has blanketed central Canada and the northern U.S., prompting widespread air quality alerts.

The New York State Department of Environmental Conservation has issued an Air Quality Health Advisory for the Lower Hudson Valley, New York City and Long Island, until midnight Tuesday, Aug. 5. NYSDEC said ground level ozone and particulate matter in the air due to wildfires in Ontario could exceed safe air quality index levels over 100.

A stretch of southern Ontario remains under a special air quality statement today amid smoke from wildfires burning in parts of the country. Environment Canada says smoke from forest fires can cause reduced air quality and visibility that can fluctuate throughout the day.