(NEW YORK) — With over 100 active wildfires burning in Canada, wildfire smoke has drifted across the border into the United States, prompting Minnesota officials to issue the state’s first air quality alert of 2024 on Sunday.

Several of the string of Canadian wildfires have been labeled “out of control,” according to officials, who placed 40 out of the 140 active fires in this category.

Most of the active wildfires, 91 to be exact, are in British Columbia and Alberta provinces.

In the U.S., wildfire smoke has reached states from Montana to Wisconsin but is especially heavy in Minnesota on Sunday.

Minnesota’s air quality alert was issued Sunday and will remain in place through Monday.

The Air Quality Index (AQI) for much of northern Minnesota has been between 150 and 200 today, which is “unhealthy” and at times has gone above the 200 AQI mark, into a “very unhealthy” zone.

Bemidji, a city in northern Minnesota, recorded a 212 AQI on Sunday, where residents could smell the smoke in the air at these levels and placed the town among the worst air quality locations in the world.

Overnight, Minneapolis, Minnesota, will have medium to heavy smoke levels reaching the surface, with officials warning residents, especially those with allergies, to make sure their windows are closed Sunday night to Monday morning.

By sunrise on Monday, the wildfire smoke in the U.S. will likely be much weaker, with medium levels reaching from Wisconsin to southern Minnesota.

By Monday evening, Omaha, Nebraska, is projected to experience some hazier skies due to the flow of the wildfire smoke.

The effects of wildfire smoke are an increasing worry across the United States, that is only expected to worsen, according to a study released in February.

By mid-century, the effects of wildfire smoke could bring startling health risks to 125 million Americans, according to First Street Foundation.

In June 2023, smoke from the Canadian wildfires blanketed parts of the Northeast and Midwest with a thick, orange haze.

Eighteen states, from Montana to New York and as far south as Georgia, were under air quality alerts, according to AirNow at the time. New York City topped the list of the world’s worst air quality rankings by a landslide, according to IQ Air.

Wildfire smoke poses startling health risks to everyone, but especially individuals with existing health conditions. Wildfire smoke is associated with strokes, heart disease, respiratory disease, lung cancer and early death, according to the EPA.

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