Wildfire smoke causes flight delays across Northeast. Here's what to know about the disruptions.

Travelers flying in or out of the Northeast may want to check on the status of their airport on Thursday, with wildfire smoke from Canada causing more flight disruptions for a second day. 

On Thursday morning, the Federal Aviation Administration put a ground stop on departures from Philadelphia International Airport, citing low visibility, while departures from LaGuardia airport in New York City had an average ground delay of almost an hour, according to agency data.

The FAA tweeted Wednesday morning that it would "likely need to take steps to manage the flow of traffic safely into New York City, DC, Philadelphia and Charlotte."

In addition to the ground stop on departing flights from Philadelphia, the agency added that it had paused in-bound flights on Wednesday morning to Philadelphia, as well as for New York City's LaGuardia, coming from the Northeast, Mid-Atlantic and Ohio due to low visibility. 

The agency also issued a ground delay for Newark airport on Thursday morning.

The delays and ground stops come after all flights to LaGuardia were paused on Wednesday, while New York City's John F. Kennedy International Airport experienced arrival and departure delays. Images from New York City on Wednesday showed an apocalyptic-looking scene, with its skyline dimmed by smoke and the air a burnt-orange color. 

The Northeast has been blanketed by smoke from the Canadian wildfires, prompting warnings about air quality across the region and prompting schools to cancel after-school events and employers to tell workers to stay home. 

Passengers can check real-time flight information at the FAA's website, U.S. Secretary of Transportation Pete Buttigieg tweeted on Wednesday evening.

Meanwhile, some airlines urged travelers to check their apps and websites to monitor for delays or other problems. 

In:
• Philadelphia International Airport
• Federal Aviation Administration
• Wildfire
• LaGuardia Airport
• Wildfire Smoke
• Ronald Reagan Washington National Airport
• Newark Liberty International Airport