Central and northern Wisconsin are under an air quality advisory due to Canadian wildfire smoke, according to the National Weather Service in Sullivan.

In those portions of the state, people can see smoke in the sky, and in some areas, on ground level, said Mark Gehring, NWS meteorologist.

Visibilities are ranging from 4 to 7 miles in parts of west central and northern Wisconsin, as well as southern Minnesota, Gehring said.

"That's from the smoke from the Canadian fires that flared back up now that spring has come," he said. "And, those fires are kind of on the border of British Columbia and Alberta — the northern part of those provinces, so way up in northwest Canada."

"People with heart or lung disease, older adults, and children should avoid prolonged or heavy exertion; everyone else should reduce prolonged or heavy exertion," the advisory said.

The smoke could cause breathing issues for sensitive groups, Gehring explained. He recommended that sensitive groups in the effected areas should stay indoors as much as possible with their windows closed and limit time outside.