Haze blankets the Ohio River in downtown Cincinnati as seen from Devou Park in Covington, Kentucky, on Monday, June 2, 2025. Smoke from the Canadian wildfires is affecting the Midwest and the East Coast.

Smoke from wildfires raging in Canada has drifted into the United States, affecting air quality as far south as Florida and creating a "very unhealthy" situation in parts of Minnesota on June 3, according to forecasters.

The smoke is expected to waft across the country, causing a moderate air quality level over much of the East Coast by the end of the day, according to the air quality forecast at AirNow.gov.

The entire state of Iowa and most of Minnesota and Wisconsin are under an air quality alert through at least midweek, with parts of Minnesota seeing unhealthy to very unhealthy air quality levels from smoke particulates. A gray haze from the smoke could be seen in Cincinnati on June 2, the Cincinnati Enquirer, part of the USA TODAY Network, reported.

There are over 200 wildfires burning in Canada as of June 3, with over 100 classified as "out of control," according to the Canadian Interagency Forest Fire Centre. The fires have forced thousands to evacuate. On June 2, the National Interagency Fire Center in Boise, Idaho, announced that 150 federal firefighting personnel from the United States are headed across the border to help fight fires in the provinces of Alberta and Manitoba.

Multiple states issue air quality alerts

Several Midwestern states issued air quality alerts on June 3 as smoke particulates began to pose health risks to residents. Minnesota, which has had air quality alerts in place for several days, slightly narrowed its alert coverage to all but the northwest portion of the state through at least noon on June 4.

Iowa issued a new air quality alert covering the entire state through June 5, warning people to avoid outdoor activity.

"Intermittent heavy smoke is expected to impact most of Iowa over the next few days at levels considered unhealthy for sensitive groups or even unhealthy for healthy individuals," the Iowa Department of Natural Resources said.

Almost all of Wisconsin and portions of Nebraska and Michigan also had active alerts on June 3.

Where is smoke impacting U.S. air quality?

Wildfire smoke has been impacting U.S. air quality for several days, starting in states bordering Canada, including the Dakotas, Minnesota and other Midwestern states.

The smoke has drifted south and east, creating moderate air quality levels for a large swath of central and southeastern states, all the way through Florida, according to AirNow.gov. By the morning of June 3, air quality in Tallahassee, Jacksonville and Gainesville, Florida, was at a moderate level.

Forecasters at FireSmoke Canada predict the smoke will waft over much of the East Coast on June 3, covering major cities including New York, Washington, Philadelphia and Boston. The AirNow.gov forecast shows these population centers receiving moderate air quality levels during the day.

Most of the smoke has remained high in the atmosphere, with little impact on health outside of Minnesota and surrounding states, according to AccuWeather. Some got to see sunsets and sunrises tinged red over the weekend because of the smoke, the outlet reported.

Some of the more impacted regions in the Northeast, Midwest and Plains are among those that also experienced unhealthy air quality in the summer of 2023 due to smoke from out-of-control fires in Canada at the time. Then, skylines in several major cities were blanketed by an orange haze and air quality was abysmal for millions of Americans.

How to stay safe from Canadian wildfire smoke

If air quality worsens in your area due to wildfire smoke, it's a good idea to limit time outdoors, experts say.

The small particles in wildfire smoke can cause burning eyes, a runny nose, a scratchy throat and can affect the heart and lungs, making it harder to breathe. It can also cause headaches and bronchitis.

Avoid physical exertion, including indoors, if air quality becomes unhealthy. While inside, keep windows and doors shut. Leave off any air conditioning or fan systems that pull air from outside, and use air filters or air purifiers. If you can’t buy a commercial portable air filter, you can create your own. One example is the Corsi-Rosenthal box made from simple materials of an air filter, box fan and duct tape.

If you must go outside, you should wear a high-quality, well-fitting N95 or P100 respirator mask to protect yourself. Keep your trips outside short.

You should also watch out for your pets when air quality is bad because they can't wear a respirator mask to protect themselves, but still may need to go outside. Keep their bathroom trips outside short, and watch out for signs of distress such as red or watery eyes and nose, coughing or gagging and increased respiratory rate.

You can monitor air quality in your area at AirNow.gov.

Canadian wildfire locations

Most of the active Canadian wildfires, 74, are in British Columbia, followed by 56 in Alberta, 25 in Manitoba, between 16 and 19 each in Ontario and Saskatchewan, and a handful more spread across other territories.

See where wildfires are burning in the United States and Canada:

Air quality index explained: What do the colors mean?

The air quality index, or AQI, measures the air quality and level of health concern it presents as measured by the Environmental Protection Agency. The AQI is measured on a scale of 0 to 500. The higher the AQI values, the greater the level of air pollution from ozone, smoke particulates and other pollutants there is, according to AirNow.gov.

Each level of health concern is also assigned a corresponding color, with green representing "good" ranging to maroon representing "hazardous." Here's what the colors and levels mean:

0-50: Code green air is deemed "good." Air quality is considered satisfactory, and air pollutants pose little to no risk for human health.

51-100: Code yellow air is considered "moderate." While this air quality is still regarded as "acceptable," some people may begin to experience health impacts, especially those who are sensitive to air pollution.

101-150: Code orange is "unhealthy for sensitive groups." Those who are considered sensitive include those with lung diseases, those who have asthma, older people, children, teenagers and those who are active outdoors, according to the National Weather Service.

151-200: Code red is "unhealthy" for everyone. The general public may begin to experience health impacts, while those in sensitive groups will have more serious health effects.

201-300: Code purple is considered "very unhealthy." Health alerts are generally issued during this color, and the health risk has increased for everyone.

300+: The last is code maroon and is considered "hazardous." This will usually prompt a health warning, and everyone is likely to be affected.

‒ Olivia Munson

This article originally appeared on USA TODAY: Canadian wildfires are having big impact on US air quality

Reporting by Jeanine Santucci, USA TODAY / USA TODAY

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