As wildfires spread across Canada, air quality in the U.S. continues to be impacted, and people sensitive to air pollution could face “serious health effects,” according to a government website that tracks air quality in the United States.
There are 59 uncontrolled wildfires and 108 controlled wildfires across Canada as of Wednesday, July 30, the country’s National Wildland Fire Situation Report said on its website. To date this year, there have been 3,582 fires.
Fires have burned nearly 1.5 million acres since the start of 2025, according to the country’s report.
The smoke floating over the border shared between America and Canada is now impacting air quality in states as far south as Texas, AirNow’s data shows. The EPA has declared the air quality in states near the Canadian border as “unhealthy or “unhealthy for sensitive groups.”
See maps and impacted states.
See map of Canadian wildfires
See map of US wildfires and smoke
Which states are most affected by the Canadian fires?
As of 9 a.m. ET on Tuesday, Aug. 5, areas in the following states are “Unhealthy for sensitive groups,” according to AirNow:
People with pre-existing medical conditions, like asthma, will be more sensitive to conditions that are deemed “Unhealthy for Sensitive Groups.”
“Members of sensitive groups may experience health effects,” according to AirNow.
‘Unhealthy’ air quality
States’ air quality is measured by the EPA’s U.S. Air Quality Index, according to AirNow’s website. Values with an index of 151 to 200 are deemed unhealthy for all.
As of 9 a.m. ET on Tuesday, Aug. 5, areas in the following states have been deemed unhealthy, according to AirNow’s air quality map:
“Some members of the general public may experience health effects,” AirNow states on its website. However, “members of sensitive groups may experience more serious health effects.”
To learn if your area’s air quality is affected by the wildfires, visit AirNow’s interactive map.
Side effects of inhaling wildfire smoke
Wildfire smoke can irritate one’s eyes, nose, and throat and cause the following symptoms:
Particulate matter (PM) is one of the main components of wildfire smoke, comprised of small particles of solids or liquids suspended in the air, USA TODAY previously reported.
According to Yale Medicine, the particles can be 10 micrometers, PM 10, or as small as 2.5 micrometers, PM 2.5, and the smaller one poses a lot of health risks.
PM 2.5 is so tiny that it can easily pass people’s usual defense mechanisms and go deep into their lungs. Not only can it damage lung function, but it can also pass into the bloodstream and travel to other organs.
The following is linked to exposure to the PM 2.5:
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Decline in cognitive function
Julia is a trending reporter for USA TODAY. Connect with her on LinkedIn, X, Instagram, and TikTok: @juliamariegz, or email her at jgomez@gannett.com
This article originally appeared on USA TODAY: Air quality map shows US states most impacted by Canadian wildfires
