Residents in the Chicago area woke up Wednesday morning to a familiar and unwelcome sight: limited visibility in many locations, and a murky hue to the air.
The first reaction, of course, was to wonder whether wildfire smoke had once again drifted over the area from western Canada, where wildfires continue to wreak havoc on local ecosystems.
Unlike previous incidents however, this time the murky conditions were caused by fog, as the National Weather Service confirmed with a dense fog advisory for nearly the entire Chicago area.
McHenry, DeKalb, Kane, DuPage, LaSalle, Kendall, Grundy, Will and Kankakee counties in Illinois were all included, as were Lake, Porter, Newton and Jasper counties in Indiana.
Even after most of the fog dissipated, there were still areas of patchy fog impacting area roadways on Wednesday morning, with motorists urged to increase following distance and to use low-beam headlights where possible.
For those curious, the Air Quality Index in most of the area is significantly-better than it has been during wildfire smoke events. The city of Chicago is currently at 47 as of 9 a.m., considered “good” by federal officials.
Some other suburbs are seeing slightly-elevated numbers, with northern Will County reporting an AQI of 64 as of 9 a.m. There are some airborne particulates impacting air quality, but no alerts have been issued at this time, and conditions are expected to continue for the next several days.
More information can always be found on the AQI website via AirNow.
Soruce : https://www.nbcchicago.com/weather/smoke-or-fog-the-latest-on-chicagos-air-quality/3204054/