2025 Canada Wildfires and United States Air Quality

Large wildland fires in the Canadian boreal forest have been burning without containment in Saskatchewan and Manitoba for the last several weeks. Due to current patterns, the National Weather Service forecasts that the smoke from these fires will continue to impact large areas of the United States over the next several days. Air Quality alerts have been issued for parts of the Midwest.

To estimate the populations potentially exposed to this wildfire smoke event, we combine geospatial information on hourly forecasts of particulate matter smaller than 2.5 microns (PM2.5) from the National Weather Service’s Air Quality Forecast Guidance with Census Bureau population data. This allows us to estimate forecasted maximum PM2.5 exposure across in the contiguous United States, and to tabulate the populations in grid cells experiencing poor air quality (using the EPA’s six category AQI scale for PM2.5). The table below summarizes the characteristics of the populations exposed.

AQI Category Total Population Affected Percent Black Percent White Percent Hispanic Percent Over 65 Percent Low Income
Good 56,239,734 7.79% 58.49% 17.69% 18.38% 19.89%
Moderate 226,207,955 12.87% 53.77% 16.76% 17.68% 20.19%
Unhealthy for Sensitive Groups 27,721,015 10.48% 68.29% 9.38% 19.28% 18.96%
Unhealthy 9,595,353 14.84% 69.58% 4.98% 18.03% 21.30%
Very Unhealthy 44 0.00% 91.73% 6.03% 37.38% 26.46%
Hazardous 27 0.00% 92.26% 7.74% 14.07% 19.21%

Over 37 million people are forecasted to be exposed to air quality that is “Unhealthy for Sensitive Groups” or worse, with over 9 million forecasted to be exposed to “Unhealthy” air quality. The populations forecasted to be exposed to “Unhealthy for Sensitive Groups” air quality are less likely to be lower income, more likely to be Non-Hispanic White, and slightly more likely to be over 65 than other parts of the country. The populations forecasted to be exposed to “Unhealthy” air quality are more likely to be lower income, more likely to be Non-Hispanic White, and slightly less likely to be over 65 than other parts of the country.

Relevant Data Tool

Census Business Builder

The Census Business Builder (CBB) is a suite of services that provide selected demographic and economic data from the Census Bureau tailored to specific types of users in a simple to access and use format.

Related Sites & Resources

Page Last Revised - June 10, 2025