Environment Canada is warning that the smoke in Yellowknife will continue for several days.
Over the weekend, Yellowknife was hit with a heavy amount of smoke caused by wildfires south of Great Slave Lake.
Environment Canada says residents may experience increased coughing, throat irritation, headaches or shortness of breath.
Children, seniors and those with cardiovascular or lung disease, such as asthma, are especially at risk.
Chief Public Health Officer Doctor Andre Corriveau will be speaking with Moose FM shortly.