An air quality warning has been issued for New York City and Long Island as the wildfire raging in neighboring New Jersey has exploded to 13,250 acres.

The health advisory, impacting the five boroughs, all of Long Island and Westchester and Rockland Counties, will remain in effect for the rest of Thursday.

The poor air quality comes as a result of the wildfires in Ocean County that have torched 13,250 acres — or 21 square miles — making it one of the largest wildfires in the Garden State in decades.

The air quality index, with readings exceeding 100 on Thursday, could be unhealthy for sensitive groups, according to the federal air quality monitoring website AirNow.

That level means those with heart and lung diseases, older adults and children are encouraged to reduce exposure by avoiding time outside and strenuous activities, state officials said.

The wildfire is currently 50% contained with 12 structures threatened, according to the latest update from the New Jersey Forest Fire Service Thursday morning.

Evacuation orders have been entirely lifted for the 5,000 Lacey and Ocean Township residents along the Jersey Shore, with zero injuries being reported, the agency reported.

Multiple buildings and vehicles have been destroyed, but the massive blaze is known to have only destroyed one commercial building thus far, NJFFS said.

Officials estimate the fire might not be completely extinguished until at least Saturday.

Annually, hundreds of smaller wildfires typically burn about 7,000 acres in New Jersey, according to the Forest Fire Service.