The Twin Cities metro, western and central Minnesota will be under an air quality alert on Monday.
The Minnesota Pollution Control Agency (MPCA) issued the alert from noon Monday until 9 p.m. Ground-level ozone is expected to be high during the afternoon and evening.
Mostly sunny skies, warm temperatures and low humidity will create an environment favorable for the production of ground-level ozone, according to the agency. Ozone is produced on hot, sunny days by a chemical reaction between volatile organic compounds and oxides of nitrogen.
Another alert is possible on Tuesday afternoon due to the forecast of sunny skies and heat.
Ozone can irritate the eyes, nose and throat, aggravate lung diseases or increase the risk of premature death in people with heart or lung disease.
The air quality is expected to be unhealthy for sensitive groups, including people who have asthma or breathing conditions, children and teens, and people working or doing extended physical activity outdoors.
The air quality alert covers the Twin Cities metro, Brainerd, Alexandria, Albert Lea, Marshall, Worthington, St. Cloud, Ortonville, Mankato, Bemidji, East Grand Forks, Moorhead, Roseau, and the tribal nations of Upper Sioux, Mille Lacs, Prairie Island, Leech Lake and Red Lake.
The MPCA advises residents to take precautions: