As Canada battles its second-worst wildfire season on record, thick clouds of smoke drifted across the border, blanketing parts of the Midwest and Northeast US.
Skies turned hazy, compromising the visibility. Wisconsin, Michigan, and Minnesota experienced concerning levels of air pollution this weekend.
Parts of Illinois and Indiana were also under air quality alerts, with authorities urging people to stay indoors or limit time spent outdoors, NPR reported.
In the Northeast, states including New York, Vermont, New Hampshire, and Maine are seeing smoke-related pollution, and officials warned residents against venturing outdoors.
The way wind moves through the atmosphere is making smoke from Canada's wildfires travel to the US, National Weather Service Lead Forecaster Bob Oravec told NPR.
The wind is blowing at many levels of the atmosphere, and in many cases, it's blowing in the same direction, he said.
As the wildfire smoke rises, it gets caught in these winds and is carried along, just like how a leaf gets blown by the wind, he explained.
The Minnesota Pollution Control Agency (MPCA) on Friday announced the statewide air quality alert and mentioned it would remain in effect until Monday, August 4, at noon. The smoke is expected to reach New York City on Monday, NBC reported.
The Air Quality Index (AQI) in the region is currently between 101 and 150, which falls under the 'Orange' category. According to the Pollution Control Board, this level of air pollution is considered unhealthy for sensitive groups.
Those at higher risk are senior citizens above 65, children under the age of 14, people with respiratory conditions such as asthma or bronchitis, and pregnant women.
The smoke from Canada's hundreds of wildfires is the primary cause of the pollution. This marks the state's longest air quality alert since 2008, according to Minnesota Public Radio (MPR). The entire duration of the alert is likely to be seven days.
The country has recorded almost 4,000 wildfires already this year.
