A mask-less Joe Biden landed in Chicago as the city grapples with a second day of thick Canadian smoke sending air quality to unhealthy levels across the eastern US and even sparking warnings in New York City. Chicago's Mayor Brandon Johnson on Tuesday urged residents and visitors alike to don masks for the duration of the air-quality alert as the thick smoke from Canadian wildfires seeps across the Great Lakes into the eastern and central US.

The smoke will concentrate on the Midwest and Mid-Atlantic on Wednesday and possibly push as far as northern Georgia, said Frank Pereira, a senior branch forecaster with the US Weather Prediction Center. Air quality is set to worsen from Washington to Baltimore on Wednesday, and an alert has been issued for New York City, Long Island and New Jersey, the weather service said. Unhealthy air levels are creeping across Pennsylvania and upstate New York. Read More: NY Skies Set to Darken Again With Smoke From Canada Fires

Biden is visiting Chicago to give a speech that will outline the theory and practice of “Bidenomics.” He will also attend a fund-raising event hosted by Illinois Governor JB Pritzker.

Air quality is rated “unhealthy” to “very unhealthy” in Chicago, Indianapolis, Cleveland, Pittsburgh and Buffalo, according to AirNow’s website. In Canada, the government air quality health index has flagged risks in Toronto and Ottawa. Some of the worst air in North America right now is in Detroit, with a “hazardous” Air Quality Index reading of 337 and a government advisory to stay indoors. The AQI in Madison, Wisconsin ranges from 262 to 290, according to AirNow. There is an area of low pressure drifting east across North America and on its west side it is pulling smoke down from the Canadian fires, Pereira said. As it continues to slide to the east, more areas of the US East Coast will come under threat. The save for the East Coast could be a second low pressure system forming behind it over the Great Lakes that could push the smoke back into Canada for a few days.

The problem is that low pressure systems spin counter-clockwise and drift to the east, so eventually they all become threats.“As long as those fires continue to burn and we continue to get these areas of low pressure, they are going to keep pulling these plumes of smoke down through the eastern third of the nation here,’’ Pereira said.Across Canada, 487 fires are raging with 253 burning out of control, according to the Canadian Interagency Forest Fire Centre. Carbon emissions from the blazes are at record levels, the European Union’s Copernicus Atmosphere Monitoring Service said Tuesday. In other weather news:US: Wilting heat continues to sear down across the southern US states triggering excessive heat warnings and heat advisories from New Mexico to Florida and even Illinois.India: The annual monsoon, which accounts for about three-quarters of annual rainfall, is set to cover the entire country about a week earlier than usual even after a delayed start.Vietnam: Northern Vietnam, which grappled with power shortages recently, will likely experience a heat wave in days following Thursday.

--With assistance from Jordan Fabian and Mario Parker.

(Updates with New York alert in first paragraph.)