Sign cautioning of extreme heat danger in California

Heat waves rise near a heat danger warning sign in Death Valley National Park, California.

(Photo: David McNew/Getty Images)

Extreme Heat Expected to Impact Millions of Americans Again This Summer

"These are not your grandparents' heatwaves," said one meteorologist.

Millions of people in the United States are facing the high likelihood of extreme heat in the coming weeks, with northern states that frequently have relatively temperate summers among those where higher-than-average temperatures are expected this summer, according to federal data.

As The Guardianreported Monday, the National Oceanic and Atmospheric Administration's (NOAA) new predictions for the summer months state that most of New Mexico and Utah have a 60%-70% chance of hotter-than-normal weather, along with parts of Arizona, Texas, and Colorado.

Houston and the surrounding area has already experienced spiking temperatures that were tied to a heat dome that was positioned over Mexico for several weeks. The high atmospheric pressure drove record-breaking heat across Mexico and in Texas, as well as a powerful storm earlier this month that killed at least seven people and left hundreds of thousands of people in the Houston area without power.

NOAA's Heat Risk tool showed that on Monday, a significant stretch of southern Texas was experiencing an "extreme" level of heat, defined as including "little to no overnight relief" and affecting the health and safety of "anyone without effective cooling and/or adequate hydration."

The new tool takes into consideration whether the heat is unusual for the time of the year, whether residents get relief with cooler temperatures in the evenings, and whether temperatures pose an elevated risk of health impacts like heat stroke or heat exhaustion.

NOAA found that the entire Northeast, from Maine to New Jersey and Pennsylvania, has a 40%-50% chance of having above-average temperatures from June through August.

"We can expect another dangerous hot summer season, with daily records already being broken in parts of Texas and Florida," Kristy Dahl, climate scientist for the Climate and Energy program at the Union of Concerned Scientists, toldThe Guardian. "As we warm the planet, we are going to see climate disasters pile up and compound against each other because of the lack of resilience in our infrastructure and government systems."

The predictions come days after the consumer advocacy group Public Citizen released a report, Scorched States, about state laws that protect outdoor workers from extreme heat—and those that don't.

As many as 2,000 U.S. workers die every year from laboring in extreme heat, said Public Citizen, even though "every workplace illness, injury, and fatality caused by heat stress is avoidable, and relatively simple preventative measures—water, shade, and breaks—have proven extremely effective at protecting workers."

The Occupational Safety and Health Administration's forthcoming heat standard rules are not expected to be finalized until at least 2026, but states including Washington, Colorado, and Minnesota have issued their own labor laws to protect workers from heat-related injuries.

The Guardian pointed out that the extreme heat expected this summer will likely take hold as the Earth transitions away from El Niño—the natural phenomenon that causes ocean temperatures to rise—and toward La Niña.

"As we transition to La Niña, it still looks to be a potentially record-breaking year. That clearly suggests to me that the anthropogenic signal is there," James Marshall Shepherd, director of the University of Georgia's atmospheric sciences program, toldThe Guardian. "I am also worried about the ocean temperatures, which are very warm, particularly as we approach the Atlantic hurricane season."

"Attribution studies are pretty decisive that heatwaves will continue to be more intense and frequent" as the planet warms, Shepherd said. "These are not your grandparents' heatwaves."

Last year, scientists found that neither the hot and dry conditions that led to destructive wildfires in Canada, nor extreme heatwaves that took hold in Europe and North America, would have been as likely to occur without the planetary heating that's been linked to continued fossil fuel extraction.

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