Canadian wildfire smoke returned to Wisconsin this weekend, with unhealthy levels for people with asthma and heart disease.

Unhealthy air has invaded Minnesota, Wisconsin and North Dakota early this week as a new round of wildfire smoke from Canada has wafted into the region, choking out areas as far south as Chicago and Detroit.

KSTP FORECAST FIRST ALERT TODAY FOR TWIN CITIES/WESTERN WISCONSIN BECAUSE OF CANADIAN WILDFIRE SMOKE PRODUCING UNHEALTHY LEVELS OF SMOKE: Northwest Winds blowing over Minnesota and Wisconsin Today will bring significant amounts of Smoke from Canada Wildfires – people with Respiratory Illness should avoid long periods of time outdoors Today through Sunday morning and even Healthy