By most measures, air quality in Minnesota has improved since the 1980s ‒ even though sophisticated new equipment allows the state to detect more pollution than it could 30 years ago.
Annual state average air quality index (AQI)
NOTE: AQI is a standard of measurement with a range from 0 to 500. Values below 100 are generally thought of as satisfactory while values above 100 are considered to be unhealthy.