An approaching cold front is pulling smoke from Canadian wildfires down to ground level, and areas of unhealthy, very unhealthy, and hazardous air quality are being measured across much of Alberta, Saskatchewan, Montana, Minnesota, and North and South Dakota. This smoke is expected to impact Iowa on Thursday and Friday, May 18-19, according to the Iowa Department of Natural Resources.

The air quality in Northwest Iowa was expected to be impacted first on Thursday morning, with a band of heavy smoke working its way through the state from northwest to southeast. The smoke is expected to impact central Iowa Thursday evening. Through the overnight hours, northwest winds will move the smoke out in the same pattern, with clearing beginning in far Northwest Iowa by tomorrow morning. Cleaner air statewide is forecast by Friday afternoon. However, intermittent and patchy smoke episodes are possible even throughout the weekend.

Unhealthy levels are anticipated across Iowa as the smoke passes through. Twenty-four-hour averages may reach unhealthy levels for sensitive groups, and levels considered unhealthy for everyone may be measured. Sensitive groups include older adults, those with respiratory or heart disease, and children. The health impacts of the smoke can be reduced by limiting prolonged outdoor exertion until air quality conditions improve.

Real-time air quality maps and information about the air quality index can be found here. A graphic approximation of the extent and trajectory of the smoke plume can be seen on the map here.