Chicago Weather

Chicago's air quality ranked worst in the world amid heavy Canadian wildfire smoke

Chicago Department of Public Health Commissioner Dr. Allison Arwady said reaching such a level is "unusual" in the Chicago area

NBC Universal, Inc.

Air quality levels in Chicago reached the worst in the world Tuesday as all of northern Illinois went under an air quality alert, with "very unhealthy" levels reported due to Canadian wildfire smoke.

According to the World Air Quality Index, which ranks cities across the globe from worst air quality to best, Chicago currently holds the no. 1 spot -- and that was before levels rose even higher Tuesday morning.

Chicago's air quality entered "very unhealthy" territory just before noon Tuesday.

According to the government air quality website, AirNow, the PM2.5 -- an air pollutant also known as fine particulate matter, which is causing much of the haze in the region -- reached 209 as of 11:30 a.m. Anything over 200 is considered "very unhealthy." By 1 p.m. that number had climbed to 228.

The National Weather Service also issued an air quality alert around that same time that remains in effect until midnight Wednesday, though conditions are expected to be "unhealthy for sensitive groups" across Illinois Wednesday.

The NWS reported smoke from wildfires in Canada is moving into the region and "pushing air quality into the unhealthy or worse categories." The agency urged people to reduce or limit outdoor activities.

Chicago Department of Public Health Commissioner Dr. Allison Arwady said reaching such a level is "unusual" in the Chicago area.

"It's actually pretty unusual for us to fall into it based on that PM2.5," she said. "Our ozone is actually good right now, so it's the PM2.5 - it's at a higher level."

What should you and shouldn't you do?

Chicago Mayor Brandon Johnson on Tuesday released a statement about Chicago's "unhealthy" air quality.

"The City of Chicago is carefully monitoring and taking precautions as the U.S. Environmental Protection Agency has categorized our Air Quality Index as 'unhealthy' due to Canadian wildfire smoke present in the Chicago region," the statement read. "We recommend children, teens, seniors, people with heart or lung disease, and individuals who are pregnant avoid strenuous activities and limit their time outdoors."

Those recommendations fall in line with what AirNow recommends at "very unhealthy" levels.

People with heart or lung disease, older adults, children and teens:

  • Avoid physical activities outdoors.

Everyone else:

  • Avoid strenuous outdoor activities.
  • Keep outdoor activities short.
  • Consider moving physical activities indoors or rescheduling them.

In addition to limiting time outside, Johnson said Chicagoans may consider "wearing masks" due to the "unsafe conditions."

"For additional precautions, all Chicagoans may also consider wearing masks, limiting their outdoor exposure, moving activities indoors, running air purifiers, and closing windows," Johnson's statement continued. "As these unsafe conditions continue, the City will continue to provide updates and take swift action to ensure that vulnerable individuals have the resources they need to protect themselves and their families."

Contact Us