Skies across major U.S. cities were a murky grey this week against a blood orange sun as smoke choked the East Coast.
New York City saw its worst air quality in more than 14 years, with the Air Quality Index reaching into the 160s on Wednesday morning.
And this is not the first time this has happened either.
In September 2020, NASA's Earth Observatory satellites tracked smoke plumes as they were swept from west to east, spreading over much of the continental U.S.
Last year was witness to unprecedented fires that turned the San Francisco Bay Area a burnt orange color in the midst of the COVID-19 pandemic.
"We’re seeing lots of fires producing a tremendous amount of smoke, and … by the time that smoke gets to the eastern portion of the country, where it’s usually thinned out, there’s just so much smoke in the atmosphere from all these fires that it’s still pretty thick," David Lawrence, a meteorologist with the National Weather Service, said Tuesday. "Over the last two years we’ve seen this phenomenon."
Now, wildfires are active in 13 states and 83 fires have already burned nearly 1.3 million acres, according to the National Interagency Fire Center.
There are 19,300 firefighters and support personnel working to fight the blazes.
Jet streams are bands of strong wind in the upper atmosphere generally blowing from west to east across the world.
As fires grow on both sides of California's Sierra Nevada, the fate of this year's wildfire season remains – like the air – unclear.
Dry conditions and heat waves linked to the impacts of climate change have made each wildfire season more difficult, and extreme weather and wildfires are expected to become even more frequent and destructive.
The Associated Press contributed to this report.