Canada wildfire smoke triggers air quality alerts across US: Which states are affected?

A helicopter drops water on the Brunswick Complex wildfires near North Bend, British Columbia, Canada July 11, 2026.  BC Wildfire Service/Handout via REUTERS.

Millions of people across the Midwest and Northeast United States are facing unhealthy air conditions as smoke from large wildfires burning in Canada and Minnesota spreads across the region, prompting air quality alerts and health warnings.

Here’s what you need to know.

Why is wildfire smoke spreading across the US?

Large wildfires burning in Canada and northeastern Minnesota are producing massive plumes of smoke that are being carried south and east by prevailing winds.

Meteorologists say the smoke is expected to spread across much of the Midwest, Great Lakes and Northeast, reducing visibility and significantly worsening air quality.

Which areas are affected?

Minnesota has issued an air quality alert through Friday, with the heaviest smoke expected in the state’s northeast, including Two Harbors and the Grand Portage Tribal Nation, where air quality could reach hazardous levels.

Smoke is also expected to affect:

The Twin Cities metro area

Alexandria, Minnesota

Michigan

Wisconsin

Maine

Northern Pennsylvania

Detroit

Milwaukee

Western and central New York

Parts of the New England coast

Washington, D.C. (by Thursday)

Residents in parts of Maine have already reported yellowish and brownish skies due to the smoke.

Why are officials concerned?

Health officials warn that wildfire smoke contains fine particulate matter (PM2.5)—tiny airborne particles that can penetrate deep into the lungs and even enter the bloodstream.

Exposure can cause:

Shortness of breath

Persistent coughing

Eye and throat irritation

Dizziness

Fatigue

Worsening of asthma and other lung diseases

Increased risk for people with heart conditions

Long-term exposure to fine particulate pollution has also been linked to premature deaths.

Who is most at risk?

The smoke poses the greatest risk to:

Children

Older adults

Pregnant women

People with asthma or COPD

Individuals with heart disease

People with weakened immune systems

In areas where air quality reaches hazardous levels, health officials say everyone—not just vulnerable groups—is at risk.

Heat and smoke create a dangerous combination

Forecasters say the smoke is arriving alongside extreme heat, increasing health risks.

“The two things coinciding with each other is not good from a health perspective,” National Weather Service meteorologist Tyler Hasenstein said.

Heat can place additional stress on the body, while smoky air makes it harder to breathe, creating a potentially dangerous combination.

How can you protect yourself?

Health experts recommend:

Staying indoors as much as possible

Keeping windows and doors closed

Running an air conditioner or air purifier if available

Avoiding strenuous outdoor activities

Wearing a well-fitting N95 mask if you must go outside

Monitoring local air quality alerts before spending time outdoors

When will conditions improve?

Forecasters expect smoke to continue affecting parts of the Midwest and Northeast through the week. Conditions may gradually improve after weather systems shift and a cold front moves through some areas, helping disperse the smoke. Until then, officials urge residents to follow local air quality advisories and limit outdoor exposure whenever possible.

(With AP inputs)

Source

Posted in US

Leave a Reply

Your email address will not be published. Required fields are marked *

1 + eight =