The Illinois Environmental Protection Agency says the air pollution action day designation will remain in effect for the Chicago area, including Evanston, through midnight Monday.
However the National Weather Service says wildfire smoke haze will exit the area during the day.
The state says small particulate levels were just barely into the “unhealthy” range at 151 micrograms per cubic meter as of 10 a.m. Monday, with the level expected to fall to the moderate level, below 100, by Tuesday.
By 10:30 a.m. Monday, monitoring stations in the area were reporting levels already reduced to the “moderate” range.
The IEPA action alert forecast that through Monday the level would be unhealthy for sensitive groups.
The City of Evanston announced that because of improving air quality index numbers all Evanston beaches will be open for swimming on Monday.