Deadly and historic wildfires in the West are sending smoke as far away as the East Coast, officials said.
The smoke was creating a hazy appearance in skies over part of Virginia, the National Weather Service said. It was also affecting New York City's skies.
At least 36 deaths have been linked to the fires in California, Oregon and Washington state.
In Oregon, 10 people have died and thousands have been displaced.
"Without question, our state has been pushed to its limits," Oregon Gov. Kate Brown said at a news briefing Monday.
Nearly three dozen fires were active Monday night, according to state data. Around 1 million acres had burned, and more than 1,100 residences have been confirmed destroyed, according to the state emergency management department.
Twenty-two people were being called missing persons, according to the emergency management department.Washington state has seen one death, and 25 are dead in California.
In California, where more than 16,500 firefighters are battling 28 major wildfires, the death toll grew by one Monday after officials in Butte County discovered the remains of someone believed killed by the blaze, Sheriff Kory L. Honea said.
The state's deadliest fire, the North Complex in the Sierra Nevada Mountains region north of Sacramento, has now claimed at least 15 lives.
The inferno, driven by high winds, moved into Butte County and caused major damage to the communities of Berry Creek, Feather Falls, Brush Creek and others, Cal Fire has said.
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More than 3.2 million acres — an area larger than Connecticut — have burned in California since the beginning of the year, and more than 4,200 homes or other structures have been destroyed, according to the California Department of Forestry and Fire Protection, known as Cal Fire.
After some help from the weather, so-called "red flag" conditions returned Monday to the northeastern part of the state, the agency said.
The largest fire in modern California history, the massive August Complex which as of Monday afternoon had burned more than 755,600 acres in Northern California, was 30 percent contained. That fire was started by lightning last month.
President Donald Trump visited California on Monday, as Gov. Gavin Newsom and other officials raised the issue of climate change for playing a role in the fires.
Trump interjected at one point and said, "It will start getting cooler." After California Department of Natural Resources Secretary Wade Crowfoot said he wished the science agreed, Trump replied: "I don't think science knows, actually."
Former Vice President Joe Biden on Monday called Trump a " climate arsonist" and called for action. Climate change "requires action, not denial," he said. "It requires leadership, not scapegoating."
Oregon's governor asked the president to issue a major disaster declaration. He previously issued an emergency declaration for the state, which frees up federal aid.
The state's Congressional delegation urged that the major disaster declaration be approved, writing in a letter that the confirmed fire-related deaths are likely to increase, and that "entire communities have been destroyed."
Cooler weather is forecast in Oregon for the end of the week, which "will be a tremendous help," Brown said, but that "the smoke blanketing the state is a constant reminder that this tragedy has not yet come to an end."
The Holiday Farm Fire, in Lane County east of Eugene, has burned more than 160,000 acres and destroyed homes, including those of Upper McKenzie Rural Fire Chief Christiana Rainbow Plews and a dozen volunteer firefighters. A fire station was also destroyed.
Brown hailed the fire chief as heroic for immediately ordering a level three evacuation — which means people must leave immediately — which allowed residents to escape. "She and her team remind us of why we love this state," Brown said.
The more than 1 million acres that have burned in Oregon is double the average of around 500,000 during an entire wildfire season, the Oregon Congressional delegation said.
The state is also facing its worst drought in more than 30 years, which has resulted in extremely dry forest conditions, they said.