Smoke from Canada's wildfires has spread extensively across the United States, prompting air quality alerts from the Midwest to the Northeast. The wildfire season in Canada is currently the second-worst on record, with intense heat fueling the fires. This has resulted in deteriorating air quality in several major U.S. cities, including Chicago, New York, Minnesota, and areas from Minnesota to Maine. The heavy surface smoke drifting southward has caused unhealthy air quality levels, particularly in parts of Minnesota, where alerts remain in effect despite otherwise mild weather conditions. The smoke's impact on health is being felt across North America as authorities continue to monitor the situation amid ongoing extreme heat warnings for the Northeast, Northwest, and Southwest regions of the U.S.