Smoke from hundreds of wildfires burning across the Canadian Prairies has significantly deteriorated air quality across large parts of Canada and the United States. Cities such as Minneapolis and Chicago have been ranked among the world’s most polluted due to the wildfire smoke. The haze has extended from the Midwest to the Northeast US, including major urban centers like New York City, Boston, and Toronto. Air quality alerts and health advisories have been issued in at least 10 US states, including New York, Minnesota, and Connecticut, as well as in southern Ontario. Sensitive groups such as young children, older adults, and individuals with heart or respiratory conditions are advised to limit strenuous outdoor activities. The smoke has also disrupted air travel in Boston and created hazy skies and red sunsets across the affected regions. Forecasters predict that smoky conditions and poor air quality will persist in the coming days across much of Canada and the US Northeast. Meteorological factors such as high pressure systems are influencing the dispersion and persistence of the smoke. The widespread impact of the Canadian wildfires is causing ongoing public health concerns in both countries.