Around 120 million people are under some sort of advisory amid a series of slow-motion disasters, with scientists warning of tough summer months ahead.
The United States has been walloped by climate-related catastrophes with raging floods, devastating fires, powerful thunderstorms and a dangerous heat wave affecting a third of the population.
Around 120 million people were under some sort of advisory on Tuesday as a heat wave scorched the Upper Midwest and the Southeast.
A series of slow-motion disasters has gripped the country as it enters summer, with warnings of misery for months to come in some areas.
"A dome of high pressure is expected to generate well-above-normal to record-breaking temperatures across the region both today and tomorrow," with heat indices "well into the triple digits in many locations," the National Weather Service said.
Parts of Indiana, Kentucky and Ohio were warned to expect the mercury to reach 43 Celsius.
NWS meteorologist Alex Lamers said the high-pressure dome was sparking extreme events around its periphery.
"A lot of times you get a pretty big heatwave and if you look around the edges of that you'll see thunderstorms and tornadoes, flash flooding, extreme rainfall," he told the AFP news agency.
The heat dome's northern edge, where high temperatures collided with colder air, saw some violent storms on Monday.
Hundreds of thousands of people were without power in the Midwest after thunderstorms tore through the area.
That cold front was expected to bring more unsettled weather, with hail and damaging winds forecast.
Further west, dramatic photographs and videos published by the National Park Service showed the devastation wreaked by flooding in Yellowstone, the country's oldest national park.
The 8,900 sqkm park in Wyoming state, which is home to the famous Old Faithful geyser, was shuttered on Monday after a flooded river swept away roads and cut off a nearby community.
Rangers warned of "extremely hazardous conditions" and told anyone still in the park to get out.
"Flood levels measured on the Yellowstone River are beyond record levels," the NPS said on its website.
"Preliminary assessments show multiple sections of roads throughout the park have been either washed out or covered in mud or rocks, and multiple bridges may be affected."
Furnace-like conditions in West
There were also warnings of excessive heat for parts of California and Arizona, which were blasted by furnace-like conditions at the weekend.
The soaring temperatures, coupled with a lengthy drought are worsening seasonal wildfires.
Two huge blazes, each of more than 120,000 hectares, continued to rage on Tuesday in New Mexico.
Dozens of other fires have sprung up throughout the region.
Fire chiefs are warning that 2022 looks set to be a terrible year for wildfires.
"Given the fuel conditions, the fire conditions that we're here talking about, I foresee a very tough four, five, six months in front of us," Orange County, California Fire Chief Brian Fennessy said last week.
Lamer, of the National Weather Service, said while it was difficult to conclude the changing climate was behind an individual episode, global heating was an underlying factor.
"Any weather event that you're looking, there's some combination of bad luck, the atmosphere has to be set up in a certain way," he said.
"But they all happen in the context of climate, and basically climate change loads the dice and makes more extreme outcomes more likely."