Chicago residents are once again dealing with dangerous air conditions this week, as smoke drifting down from wildfires burning across Canada continues to blanket the region.
The Illinois Environmental Protection Agency and the National Weather Service have kept air quality alerts active for the city and surrounding suburbs, warning that pollution levels have repeatedly climbed into the hazardous range on the Air Quality Index.
Earlier this month, readings in parts of Cook County reached record highs, with some monitors showing an AQI over 600, a level considered extremely hazardous. That reading broke the record for the worst air quality in Cook County history.
The smoke forced the Chicago Park District to shut down beaches and outdoor pools, and it led to the postponement of at least one Chicago Fire home match because of health risks to players and fans.
Conditions have swung back and forth since then. Air quality improved briefly before worsening again over the weekend as new smoke rolled in. Health officials say the shifting pattern is tied closely to wind direction, since the smoke itself is coming from hundreds of miles away.
What is driving the smoke
The source of the haze is an unusually active wildfire season across Canada. Nearly 900 wildfires are currently burning throughout the country, and experts say the situation is unlikely to resolve quickly.
A public health researcher at the University of Illinois Chicago noted that based on the pattern seen in recent summers, Chicago area residents should expect ongoing swings in air quality tied to wildfire activity and shifting weather systems.
Officials have pointed to a broader climate pattern behind the repeated smoke events. Warmer, drier spring conditions across Canada have made forests more prone to burning earlier and more intensely in the year, a trend scientists link to long term changes in temperature and rainfall patterns.
Health risks and precautions
Doctors are urging caution, especially for children, older adults, pregnant women, and anyone with asthma or other respiratory conditions. Local emergency rooms have reported a noticeable uptick in patients dealing with breathing trouble tied to the smoke exposure.
Health experts recommend that residents limit time outdoors during the worst stretches, keep windows and doors closed, and use an N95 or KN95 mask if they need to be outside for extended periods. Sensitive groups are advised to avoid strenuous activity altogether until conditions improve.
Meteorologists say another shift is possible in the coming days depending on wind direction, but they caution that hazy skies could return with little warning. For now, residents are being told to check daily air quality reports before planning outdoor activities, since conditions in the Chicago area have proven capable of changing quickly from clear to hazardous within a matter of hours.