Smoke from wildfires in Western Canada drifted into the Midwest and Northeast United States on Monday, blotting out blue skies and sunshine and blanketing dozens of cities with unhealthy air that prompted warnings to limit time outdoors.
It was the second time in less than a month that the borderless impact of climate change could be felt in one breath. In June, heavy smoke from Quebec fell on the East Coast and blew from New York, then Washington, west to Minnesota.
This week, like Nearly 900 fires burned across Canadathe smoke came from wildfires in the western part of the country, pouring into its southern neighbor in a wide path.
Until 7 p.m. Eastern time, nearly 70 million people in 32 states and the District of Columbia were affected by drifting smoke, according to estimates based on information from the National Oceanic and Atmospheric Administration and LandScan, a population database.
“Unfortunately, fire smoke will begin to return to the area to begin the new week,” according to the National Weather Service in the Philadelphia area.
Air quality warnings, ranging from moderate to very unhealthy, were issued by state agencies from Montana to the Dakotas and parts of other states including Nebraska, Alabama, Tennessee, Ohio, North Carolina and along the northeast.
Residents are advised to take precautions, from limiting outdoor activities to wearing masks. In Chicago, where air quality worsened over the weekend, Mayor Brandon Johnson warned children, older residents and those with heart or lung disease to limit outdoor activity.
“We know very well that the recent weather events that are strongly affecting our city this summer are the direct result of the climate crisis,” he said.
Air quality advisories were also in effect in areas of it Massachusetts.
Governor Kathy Hochul of New York; on Sunday issued air quality health guidelines for Monday. Air quality in parts of New York state was expected to reach unhealthy levels for all residents, while conditions in the Lower Hudson Valley, New York and Long Island were expected to be unhealthy only for sensitive groups. Air quality across the region worsened by 6:30 p.m. on Monday, with parts of the city and state exceeding 100 on the air quality index.
“New Yorkers should once again prepare for smoke from wildfires in Western Canada to affect our state's air quality this week,” Ms. Hochul said in a statement, adding that officials are activating alerts roads and public transit systems and ensure that masks were available for distribution in counties across the state.
Rochester's air quality index started at 141 early Monday, while Buffalo's index was at 116, but those readings were improving in both cities by late afternoon. New York City officials said the conditions, considered unhealthy for sensitive groups, could persist for the first part of the week.
The index it runs from 0 to 500. The higher the number, the higher the level of air pollution. An AQI of 101 or more is considered unhealthy for sensitive groups and 201 or more is considered very unhealthy for anyone.
So far, air quality warnings have not been as bad as in early June, when there were readings above 400 on the east coast, signaling a dangerous level.
But by 10 p.m. Eastern time Monday, cities across the Midwest and East reported some of the worst air quality in the country, according to of the Environmental Protection Agency. Billings, Mont., and Fort Wayne, Ind., had an AQI of 161, while the Cleveland area was 157. Conditions continued to improve through the afternoon.
The forecast is expected to cause “unhealthy for all” conditions in areas closer to the Canadian border, according to AirNowa website run by the EPA, which oversees air quality throughout the United States.
The Ohio Environmental Protection Agency said its advisory was in effect until Monday. In the southwestern region of the state, said the residents to limit the use of their vehicles, refrain from mowing lawns and avoid burning firewood and yard waste.
Local officials also advised residents to limit outdoor activity or use their cars and wear masks. The message was echoed by Buffalo — where Mayor Byron W. Brown said the residents to take precautions — in Chicago, where an air quality alert was in effect until Sunday night.
In Pennsylvania, where the Department of Environmental Protection has issued a statewide “code orange” alert, officials suggested residents and businesses help by limiting the burning of leaves, trash and other materials and avoiding the use of moving lawn and garden equipment with gas.
Wildfire smoke from Canada is expected to linger until Tuesday, driven by northwesterly winds, the National Weather Service said.
Early last month, the level of particulate matter in the air from smoke became so unhealthy that many US cities set records. In some places, it was dangerous to breathe everywhere from Minnesota and Indiana to parts of the Mid-Atlantic and South.
Visibility was reduced to astonishing degrees in cities including New York, Toronto and Cincinnati. In some places, smoke from the fires covered the sky in an orange haze. This smoke can be traced to the fires burning in Quebec.
