The Colorado Department of Public Health and Environment (CDPHE) has issued an air quality health advisory for wildfire smoke in the Denver metro. It’s in effect until around 4 p.m. Friday.

What we’re watching out today are the fine particulates in the air. Those particulates are debris in wildfire smoke that are very, very, very small and can get enter your lungs and bloodstream. 

CDPHE has labeled the current measurement of those particulates as “UNHEALTHY for sensitive groups.” That includes groups like the elderly, folks with heart disease or respiratory illness and infants. For the most part, the state recommends that you stay indoors and to limit time spent outside.

Sadly, we may be in for more wildfire smoke advisories over the next few days.

Smoke from wildfires in Canada are the source of our poor outlook, according to CDPHE. About 90 wildfires were reportedly burning in Alberta in western Canada this week.

CNN reports that the smoke is moving into the central U.S. and could linger for a few days.