For the second straight year, wildfires from Canada have been causing air quality concerns in the U.S.
Parts of Iowa are under an air quality alert on Tuesday as the National Weather Service says that smoke from a cluster of wildfires in northern Alberta and British Columbia has drifted into the Midwest.
However, not as many areas expect to see unhealthy air quality as on Monday.
According to the U.S. Air Quality Index, the air quality in cities like Minneapolis and Bismark, North Dakota, was considered "unhealthy" for parts of Sunday and Monday. On Tuesday, the air quality is expected to be "good" in Minneapolis and "moderate" in Bismark.
Canada
Canadian wildfires force evacuations and prompt air quality alerts for the US
Meanwhile, air quality in Des Moines, Iowa, is expected to be "unhealthy for sensitive groups."
Air quality is gauged by measuring how prevalent fine particles, generally 2.5 µm or smaller, are in the air. That is then put on a scale from 0-500. This is known as the air quality index.
When the air quality index reaches 101, it is considered unhealthy for sensitive groups. When it reaches 151, it is considered unhealthy for all groups; and if it goes above 201, it is considered very unhealthy.
The air quality index reached 185 on Monday in Minneapolis.
Residents of Des Moines woke up to an air quality index of 106 on Tuesday morning.
In June 2023, wildfires in eastern Canada caused significant air quality problems throughout much of the Northwestern U.S. and Midwest. The poor air quality forced some outdoor events to either be postponed or canceled.