Last week, Canadian wildfire smoke blanketed Wisconsin and caused the Air Quality Index to reach the unhealthy level for sensitive groups. Six days later, on July 31, the smoke appears to have a worse impact on the air.

MADISON, Wis. (WMTV) - As of this morning, the Air Quality Alerts for Wisconsin have now been set to expire Friday at noon. The alerts are the result of Canadian wildfire smoke impacting air quality.

Smoke impacts began in northern Wisconsin Tuesday morning and will spread south through the state by July 31. Air quality may briefly improve on July 31 before smoke returns to northern areas on Aug. 1, the DNR reports.