December 4, 2023

The Statue of Liberty stands behind a cloud of mist on July 20, 2021 in New York City.

Spencer Platt | Getty Images

SANTA MONICA, California – Wildfire smoke from Canada and the western United States spread across the continent this week, creating hazy skies and unhealthy air quality to New York, New Jersey and Pennsylvania.

In the past few days, more than 80 forest fires have burned nearly 1.3 million acres in the west experiencing a historic climate change-induced drought that has triggered dangerous drought, according to data from the National Interagency Fire Center.

In southern Oregon, the Bootleg Fire, the largest fire of the season, burned nearly 400,000 acres and has become so intense that it generates enough heat and energy to change the weather.

The British Columbia government declared a state of emergency after fires sparked dozens of evacuation orders. According to the government, there are 295 active forest fires in the region, 15 of which have ignited in the past two days.

The smoke and ash from the forest fires were carried by the jet stream and continental winds, triggering health warnings thousands of kilometers away, including the upper Midwest and the Northeast, the National Weather Service said.

CNBC policy

Read more about CNBC’s political coverage:

North winds carried forest fire smoke from the north of the Canadian border into Minnesota, causing state officials to issue an air quality alert.

In New York, a thick haze covered the Manhattan skyline and the air quality index for particulate matter hit an unhealthy range well above 100 after winds blew smoke from states like California, Oregon and Montana.

Other cities, including Philadelphia and Boston, also had AQI scores above 150, a level considered unhealthy for all humans and well above the World Health Organization’s exposure recommendations. These cities, along with Washington and Baltimore, are under air quality warnings.

Severe drought has hit more than three-quarters of the west, according to the US Drought Monitor, and climate change has created hotter and drier conditions, leading to more intense and frequent forest fires.

While it is not unprecedented for western forest fire smoke to travel long distances, it usually doesn’t happen until later in the summer and fall. The smoke also usually remains in the atmosphere at high levels and does not affect air quality at lower levels.

Health officials have suggested that people in areas with particularly poor air quality should wear filtered masks and avoid strenuous exercise outdoors.