Editor's Note: An updated story for Tuesday, June 27 can be found here. Our original story continues below.
While the frightening smoke that blanketed skylines in northeastern U.S. cities just a few weeks ago has passed, air quality in Chicago is poor to start the weekend, and it's not only because of wildfires.
Although the return of wildfire smoke is partially to blame for the Chicago area's eighth air quality action day of the year, higher ozone levels have also greatly contributed to Friday's poor readings.
Those with severe respiratory problems, the elderly, and young children should limit time outdoors in the afternoon, when the air quality is usually worse.
Higher levels of ground-level ozone are caused by chemical reactions from sunlight and emissions from our cars and industrial plants.
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During the mornings on bad ozone days, hazy skies usually caused by a temperature inversion where cooler air is trapped under warmer air just 1,000 feet above the ground are often visible.
Meanwhile, smoke from wildfires in Ontario and Quebec continues to drift into the Midwest, causing a drastic increase in PM 2.5 on Friday.
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Although some of the smoke is expected to subside on Saturday as a disruption to the upper-level northeast wind carrying the wildfire smoke is anticipated, the National Weather Service announced that an air quality action day will also be in effect tomorrow throughout the Chicago area.
Those who must spend time outdoors are advised to stay hydrated and pay attention to their body, with residents encouraged to head indoors and near an air conditioner to filter the air in the event of lightheadedness or difficulty breathing.
You can also help reduce ozone by carpooling or taking public transportation, avoid refueling in the afternoon, make sure your tires are fully inflated, and set your A/C to a higher temperature at home.
