• New York City's air pollution ranked the worst of any city in the world on Wednesday as wildfire smoke from Canada continued to drift over the area, creating a second day of orange haze over the city and prompting some residents to wear face masks outdoors.
• As of Wednesday afternoon, the city reached an AQI of 342, a level considered "hazardous" for all residents.
• The Federal Aviation Administration on Wednesday halted some flights bound for New York's LaGuardia Airport due to the smoke.

New York City's air pollution ranked the worst of any city in the world on Wednesday as wildfire smoke from Canada continued to drift over the area, creating a second day of orange haze over the city and prompting some residents to wear face masks outdoors.

As of Wednesday afternoon, the city reached an AQI of 342, a level considered "hazardous" for all residents. The city's schools are open but are not having outdoor activities as the air quality is expected to deteriorate throughout the day.

The Federal Aviation Administration on Wednesday halted some flights bound for New York's LaGuardia Airport due to the smoke. Visibility was also causing delays at Newark Liberty International Airport.

New York Gov. Kathy Hochul said the poor air quality is "an emergency crisis" and warned it could last for the next few days. "If you can stay indoors, stay indoors. This is detrimental to people's health," Hochul told reporters on Wednesday.

The MLB said in a statement that Wednesday's games between the Detroit Tigers and the Philadelphia Phillies at Citizens Bank Park and the Chicago White Sox and the New York Yankees at Yankee Stadium had both been postponed.

"These postponements were determined following conversations throughout the day with medical and weather experts and all of the impacted Clubs regarding clearly hazardous air quality conditions in both cities," the league said.

The official Twitter account of the popular musical production "Hamilton" tweeted that "the hazardous air quality in New York City has made it impossible for a number of our artists to perform this evening" but added that the show plans to resume Thursday.

City officials have advised residents to limit outdoor activity Wednesday and warned that children, older adults and people with preexisting respiratory problems are especially vulnerable.

Wildfire smoke releases fine particulate matter, called PM2.5, which enters the lungs and causes health issues such as asthma and bronchitis. PM2.5 concentration in New York City is currently 15 times the World Health Organization's annual air quality guideline value.

The New York State Department of Environmental Conservation has issued an Air Quality Health Advisory for all five boroughs. City officials have said they expect the advisory to remain in place for the next few days but added it's particularly difficult to forecast smoke conditions.

New York also extended its air quality health advisory to Thursday.

Mayor Eric Adams in a press briefing Wednesday urged vulnerable residents to remain indoors and said dangerous air quality conditions are forecast to temporarily improve later tonight through Thursday morning but continue to deteriorate Thursday afternoon and evening.

"This may be the first time we've experienced something like this of this magnitude," Adams said. "Climate change is accelerating these conditions. We must continue to draw down emissions and improve air quality and build resiliency."

Canada is on track to experience its worst-ever wildfire season, with more than 400 active wildfires currently burning across nearly all Canadian provinces and territories. Federal officials said last week that wildfires have burned more than 6.7 million acres and about 26,000 people are under evacuation orders.

The smoke from Canada's wildfires has drifted south and prompted air pollution warnings across the country.

Millions of people in the Midwest are experiencing dangerous air quality conditions, with air quality advisories in effect in southeastern Minnesota, parts of the Upper Peninsula of Michigan and areas in Wisconsin. Air quality alerts have also been posted across most of New England.

The National Weather Service in a forecast said the smoke was expected to linger through Wednesday and continue to travel further west.

Climate change is increasing the frequency and intensity of global wildfires and air pollution from wildfire smoke is also growing worse. Last year, Stanford researchers found millions of Americans are routinely exposed to wildfire smoke pollution at levels rarely seen only a decade ago.