Maps show U.S. air quality and Canada wildfire smoke forecast

An air quality map shows conditions across the United States on Wednesday as Canadian wildfire smoke is forecast to continue to spread across the country, prompting air quality alerts and advisories in multiple states.

The map shows parts of Wisconsin, Michigan, Illinois and other upper midwestern states are facing unhealthy air as of Wednesday afternoon, according to a federal measurement system called the Air Quality Index. Minnesota had experienced unhealthy air earlier Wednesday and the days prior.

The air index has six ratings: 

• Good
• Moderate
• Unhealthy for sensitive groups
• Unhealthy
• Very unhealthy
• Hazardous

Sensitive groups include those who have a heart or lung disease, as well as older adults, children and pregnant women.

Air quality advisories or alerts were issued for several states, including Wisconsin, Michigan, Illinois, Indiana, New York, Massachusetts and Connecticut, according to the National Weather Service. 

Here’s a look at where alerts will be in effect through Thursday.

Wildfire smoke could be visible in other areas but may not impact air quality. In Maryland, for example, smoke was expected to keep skies hazy overnight but remain at high altitudes, having little impact on the quality of air at the surface, CBS Baltimore reported.

The smoke is expected to have less of an effect over the next few days. These maps show where the smoke is forecast to move through Friday morning. 

More than 200 fires are burning in Canada, with over 100 of them considered out of control, according to the Canadian Interagency Forest Fire Centre. Tens of thousands of residents across three provinces have been evacuated due to the blazes.

Nikki Nolan

contributed to this report.