The Wisconsin DNR said Tuesday the air quality index is expected to reach unhealthy levels for people in sensitive groups.
The advisory applies to the following counties: Brown, Door, Kenosha, Kewaunee, Manitowoc, Milwaukee, Ozaukee, Racine and Sheboygan.
Sensitive groups include people with lung diseases, such as asthma. The group also includes children, older adults, and people who are active outdoors, including outdoor workers.
People in this group should reduce exerting themselves for extended periods of time while outdoors.
The advisory was issued at about 1 p.m. Tuesday and will end at 11 p.m. More information on air quality in Wisconsin can be found here.