Smoke has spread to the east of the country in many of the US West Coast wildfires, putting fog over New York and Washington DC.
The blasts burned vast areas of land since early August and killed at least 36 people.
They have also caused some of the most unhealthy air on the planet in many western states.
Scientists said the smoke was so high on the East Coast that it would not affect air quality.
Satellite images showed the fumes being carried by the jet stream to the East Coast – a narrow portion of high-speed winds – across the Mid-Atlantic.
The National Weather Service (NWS) in New York said the smog in the state was over 25,000 feet (7,620 m) on Tuesday.
NWS said on Twitter, “If you looked at the sky today, you would have seen a yellow or brown kilt. You were seeing smoke from the fire.”
There were also misty skies in the capital, Washington DC, where the NWS said the smoke was about 15,000-25,000 feet above ground level.
This smoke was obscuring the sun on Tuesday and meant the temperature in the city was slightly cooler, as they would not have been otherwise.
Journalist Mike Valerio shared a picture of misty skies around the Lincoln Memorial.
What is happening on the West Coast?
Dozens of wild animals have burned vast plains of land on the West Coast since early August. Strong winds and low humidity have hampered efforts to keep the blasts under control.
According to the Global Air Quality Ranking, the states of Oregon, Washington and California are experiencing some of the most unhealthy air on the planet.
Poor air quality has forced some businesses to shut down, ground flights and suspended services such as trash collection in some communities.
“Everything is covered in ashes,” California resident Twana James told the Associated Press news agency. “It’s hard to breathe.”
In parts of Oregon, air quality has become so dangerous that it has surpassed the state’s air quality index scale.
Oregon Congressman Peter DeFazio said the White House on Tuesday approved a request from the state’s governor to declare the fire a “major disaster”.
He said the decision would make more federal aid available to the state and “provide the necessary resources to rebuild our communities”.
In Los Angeles, firefighters have battled to protect the famous Mount Wilson Observatory – founded in 1904 – as a wildfire.
US President Donald Trump has blamed poor forest management for the fire.
California Governor Gavin Newsome said this week that lethal wild animals showed that the debate around climate change was “over”.
But on a state visit, Mr Trump dismissed concerns about climate change, saying that “it will start cooler, you just see”.
- The California Burned: A chilling documentary on the deadliest fire in the US for a century (available only in the UK)