Wildfire smoke worsens air quality across US

Currently, there are more than 900 active wildfires burning in Canada, including in the provinces of Ontario and Manitoba, which border the northern United States. Thick smoke from these fires traveled across the border and worsened air quality in the Northeast, Midwest, and Northwest United States over the last week.

Major cities like Chicago, New York, and Washington, D.C., all reported hazy skies due to wildfire smoke. On Thursday, Detroit was reported as having the worst air quality in the world. Several cities issued air quality alerts and urged people to stay inside.

According to the National Weather Service, heavy rains and storms could help clear the air in the Northeast and Mid-Atlantic, but the Midwest will likely continue to see dangerous levels of air pollution.

Wildfire smoke contains toxic air particles that can cause coughing and wheezing, headaches, stinging eyes, a scratchy throat, sinus irritation, chest pain, rapid heartbeat, and fatigue. People with chronic respiratory illnesses, children, older adults, and pregnant people are at a serious risk of negative side effects from wildfire smoke.

How to protect yourself from wildfire smoke

According to researchers, human-caused climate change has made wildfires both more likely and more intense. In a 2025 report from Climate Central, researchers wrote that "[p]er-person exposure to harmful wildfire smoke in the U.S. was four times higher during 2020-2024, on average each year, than during 2006-2019."

With the risk of wildfires getting higher, health experts have recommended several ways to stay safe when air quality is bad, including:

• Staying inside
• Limiting physical activity
• Keeping windows closed
• Keeping the air conditioning on
• Shutting your windows when driving
• Wearing an N95 or KN95 mask to help filter out smoke particles when outside
• Monitoring air quality reports, especially if you have health conditions

People without HVAC systems can also buy or build an air cleaner. Homemade air cleaners are called Corsi-Rosenthal boxes and cost around $100 to make. "It's a box fan, duct tape, and you need four or so of these higher-rated MERV filters to make kind of a cube," DeCarlo said.

Depending on where you live and how close you are to wildfire smoke, you may also need to wash your curtains, clean your blinds, or cover your furniture with sheets that can be washed later. According to Masoud Ghandehari, a professor of urban systems engineering at New York University, if smoke particulate embeds itself into the upholstery of your furniture, "every time you hit the upholstery, then it kind of raises in the air."