Air quality has taken a serious hit across the United States as a twofold blow of wildfires in the West and in Canada have sent smoke pouring across large sections of the country — a problem that’s set to linger for days.

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.

Each New England state has seen an uptick in the number of days over the last five years when fine particulate matter (PM2.5) or ozone exceeds air quality standards that are considered “unhealthy for sensitive groups.