Chicago air quality alert extended as Canadian wildfire smoke returns Saturday

An air quality alert will stay in place for the Chicago metropolitan area through Saturday night as smoke from wildfires in Canada moves back into the region. Meteorologist Jaisol Martinez said air quality was "moderate" on Saturday morning but could drop to "unhealthy for sensitive groups" later in the day because of elevated ozone levels. Winds are expected to bring the haze back by late afternoon, with the plume likely less intense than the one that affected the city on Thursday. Rain showers are forecast between noon and 5 p.m., and the smoke is expected to linger into Sunday.

The National Weather Service extended the alert for parts of northwest Indiana until Monday, noting that a shift in wind direction on Monday could help improve conditions. Severe-weather risk levels remain at Level 1 for most of Chicago and its north-west suburbs, and Level 2 for the southern suburbs and northwest Indiana.

Local events are adjusting to the air-quality situation. The Stan’s Donut Run is slated to proceed on Saturday, while the Roscoe Village Burger Fest has been postponed to the same day. Organizers of the Tacos y Tamales festival in Pilsen said they are monitoring conditions throughout the weekend.

Health officials warned that wildfire smoke contains fine particles that can irritate the eyes and respiratory system. Dr. Soledad Cortina noted that components of wildfire smoke are similar to those found in tobacco smoke and can have lasting health effects. Dr. Juanita Mora of the American Lung Association advised residents to limit outdoor activity, stay hydrated, and use vehicle recirculation mode to reduce exposure. HVAC technician Karol Derezinski recommended checking air-filter condition, even if the filter appears clean.

Visibility at O’Hare International Airport has been reduced, causing potential delays. The alert is set to be reassessed after Monday’s forecasted wind changes.