The Wisconsin Department of Natural Resources issued an air quality alert for all of southeast Wisconsin until noon Sunday, Aug. 3.

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.

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.