Air quality in Chicago today unhealthy for certain groups

CHICAGO (CBS) -- Poor air quality in Chicago has prompted the Illinois Environmental Protection Agency to declare an Air Pollution Action Day.

Ozone and particulate air pollution are forecast to be in Chicago's unhealthy (orange) range today.

That means people who are sensitive to pollutants should restrict their outdoor activity. Generally, ozone is lower in the morning, making that the best time to be outside. 

Fireworks also are a contributing factor in today's poor air quality, CBS 2 meteorologist Ed Curran reported. 

Tomorrow, conditions are expected to improve as temperatures become cooler after forecasted storms this evening. 

The air is not as bad as last week when the smoke from Canada's wildfires ranked Chicago's air quality the worst in the world. 

"I thought it was going to be nice until it started smelling like campfire smoke," said Will Bland, who was visiting Chicago from Washington, D.C., last week.