Wildfire smoke seeping across western and northern Minnesota Friday and into southern Minnesota on Saturday has prompted state pollution officials to issue a statewide air quality alert ahead of the weekend.

Much of Friday’s smoke stemmed from fires in western Canada, which will render air quality “unhealthy for sensitive groups,” according to the Minnesota Pollution Control Agency (MPCA). The alert extends through midday Sunday.

Pollution officials expected air quality to worsen across northern and western Minnesota Friday night.

The smoke pollution will then creep into the southern part of the state by midday Saturday, including St. Cloud, the Twin Cities and Rochester, according to the MPCA.

The MPCA cautions that groups most likely to feel the effects of the “fine particle pollution” include children, older adults, those who have breathing conditions like asthma, heart disease, high blood pressure and people planning to exercise or work outdoors.

Unhealthy air quality may trigger chest pain, shortness of breath, wheezing, coughing or fatigue, according to the MPCA. State pollution officials are advising Minnesotans to limit outdoor physical activity over the weekend and avoid air pollution hotbeds like busy roads and wood fires.

Relief is in sight. A south wind is expected to usher in cleaner air by Sunday afternoon.