Meteorologists warn week ahead in US will have dangerous temps: 'Heat is not to be played with'

Most of America's Lower 48 states are about to swelter under an unusually large, strong and long-lasting heat dome that will spike temperatures in a way that the National Weather Service calls “significant and dangerous.”

The heat wave will start this weekend and last at least a week, with some areas feeling its effects until the end of the month, meteorologists said. Temperatures will be 15 to 25 degrees Fahrenheit (8 to 14 degrees Celsius) warmer than normal in many areas, including at night, they said. Hotter nighttime temperatures are especially bad for both human health and efforts to tamp down an already active wildfire season.

“This upcoming heat wave does look pretty remarkable,” said Daniel Swain, a climate scientist with University of California Agriculture and Natural Resources. “This is going to be a long duration, widespread and high-intensity heat event that’s going to affect millions of people for over a week.”

A dome of high pressure — which traps hot air like a pot lid while blocking cooling winds and rain — will initially park over the Northern Plains, but it will be so big that it will trap sweltering temperatures across as much as two-thirds of the continental United States, three meteorologists told The Associated Press. While it will initially miss the East Coast, the heat dome will shift and wobble, maybe even spreading from coast-to-coast over the next 10 days or more, they said.

Forecasters are expecting record triple-digit highs this weekend in Nevada, Utah, Colorado, Wyoming, Idaho, Montana, North Dakota and South Dakota.

The weather service is predicting more than 90 U.S. local temperature records will be tied or broken through Wednesday, with two-thirds being overnight heat records that can hinder how the human body recovers from broiling days.

“Nights can be just as dangerous as days. If you don’t get heat relief at night, that’s going to spill out into your daytime experience and become extremely dangerous,” said meteorologist Bob Henson with Yale Climate Connections. “Heat is not to be played with. It’s just as dangerous as a tornado or hurricane that can kill you just as easily, just in a quiet and different way.”

Swain said what makes this heat wave so different is how big a warm shadow it will cast and how long it will persist.

In the past couple of weeks, major heat waves have caused extensive suffering in Europe, the U.S. East Coast and most recently the U.S. Southeast. Now any place in the United States that escaped the earlier July heat waves will get this one, Swain said.

Rain is likely to sneak below the southern edge of the heat dome and douse the U.S. Southeast during the daytime, setting up something strange, Climate Central meteorologist Shel Winkley said. Because of the added moisture and humidity, the Southeast could get record-shattering nighttime heat but below-normal daytime warmth, he said.

The weather service is predicting record nighttime heat in a number of locations from Texas to Florida to North Carolina on Saturday. Temperatures won't drop below 80 degrees (27 degrees Celsius) at night in Fort Lauderdale, Florida; Miami; Tampa, Florida; Galveston, Texas; and Charleston, South Carolina, according to the forecast.

While heat domes are not unusual in the summer, Winkley said this one stands out because of how strong it is, likely to set records for the amount of high pressure that it will contain. It's especially unusual for being so far north, he said.

It’s likely to persist so long because drought-stricken areas have less soil and air moisture that would normally slow the warming of the air, Swain said. The drier, hotter air then worsens the drought conditions and stokes more heat in a vicious cycle, he said.

This will add to wildfire risk, already bad because of the drought, he said.

The El Nino that recently formed is too young to have a pronounced impact on this heat wave, but climate change from the burning of coal, oil and natural gas clearly does, the three meteorologists said.

“We know that heat waves are becoming more intense, they’re lasting longer, they’re covering larger areas than they used to because of human-caused climate change,” Swain said. “And so when we see an event like this, we know there is at least a partial contribution by the long-term warming trend.”

Climate Central uses 20 different computer models to compare what's forecast to what would be expected in a world without greenhouse gas-caused warming as part of its Climate Shift Index. A 20,000-square-mile (52,000-square-kilometer) swath of the country from Southern California to northern Minnesota where 24 million people live this weekend will have warmth reaching the highest level on that index, meaning the heat is at least five times more likely because of climate change. Their analysis produced similar readings for the East Coast heat wave over the July 4 weekend and the recent Southeast heat wave.

“Using attribution science we know that those temperatures would be virtually impossible without the influence of climate change,” Winkley said.

The Associated Press’ climate and environmental coverage receives financial support from multiple private foundations. AP is solely responsible for all content. Find AP’s standards for working with philanthropies, a list of supporters and funded coverage areas at AP.org.

FILE - Visitors use fans as as they wait to enter the Washington Monument, July 1, 2026, in Washington. (AP Photo/Tom Brenner, File)

FILE - A vendor sells Gatorade and water bottles near the Washington Monument during a heat wave July 3, 2026, in Washington. (AP Photo/Julia Demaree Nikhinson, File)

FILE - Vendors sell Gatorade and water bottles near the Washington Monument during a heat wave, July 3, 2026, in Washington. (AP Photo/Julia Demaree Nikhinson, File)

FILE - A police officer holds ice to their neck to try and stay cool following the 2026 Nathan's Famous Fourth of July hot dog eating contest at Coney Island in the Brooklyn borough of New York, July 4, 2026. (AP Photo/Anna Connors, File)

FILE - Mickelina Papotto, of Salem, Ore., left, and Lorie Odegaard, of Gaithersburg, Md., fan themselves while waiting in line for the ferris wheel at the Great American State Fair on the National Mall, July 1, 2026, in Washington. (AP Photo/Jacquelyn Martin)

MADRID (AP) — One of Spain's deadliest wildfires on record killed 12 people overnight into Friday, authorities said, as soaring temperatures grip much of the country.

Several victims of the fire in the southern province of Almeria, a popular holiday destination, were found inside burnt-out vehicles and were thought to have died while trying to flee the flames.

Eight people have been injured and a further 23 are unaccounted for, Andalusia’s regional leader Juan Manuel Moreno said. Some 150 firefighters and 220 soldiers from Spain’s military emergency unit were battling the blaze, which has consumed more than 3,200 hectares (7,900 acres) of forest and farmland.

Regional emergency authorities said four British nationals and other unspecified foreign nationals appeared to be among the dead.

The fire broke out in a hamlet in a semi-arid area near the Sierra de Los Filabres mountains. Authorities have not confirmed the cause, but said people who called to report the fire said that a fallen power line had sparked a blaze that spread rapidly into a nearby forest.

Most of the victims died while attempting to flee and ignored shelter-in-place instructions, said Antonio Sanz, president of Andalusia’s emergency services. One group did so via a dry riverbed, which “turned into a death trap,” he said.

Seven people died while on foot after abandoning their cars, Sanz said, likely looking for a way out.

“The consequences have been terrible. Everything seems to indicate that, in the case of the deceased ... we are dealing for the most part, if not entirely, with foreign nationals,” Sanz said.

Spanish Prime Minister Pedro Sánchez expressed his condolences. “Immense sadness and desolation in the face of the terrible consequences of the fire affecting the province of Almeria,” he wrote on X.

Spain has battled frequent and severe heat waves in recent years, with temperatures often exceeding 40 C (104 F). Wind, high temperatures and little rainfall help small wildfires grow into unchecked blazes.

In June, Spain experienced several days of record-setting heat, with over 1,000 excess deaths attributed to heat.

Europe is the world’s fastest-warming continent, with temperatures increasing twice as fast as the global average since the 1980s, according to the European Union’s Copernicus Climate Change Service. Parts of Western Europe are facing their third heat wave in six weeks. Globally, 2025 was the third-hottest year on record, bringing several intense heat waves across Europe.

France is experiencing the peak of its third heat wave of the summer, with temperatures reaching 40 C (104 F) across western and central areas and around 37 C (98 F) in Paris.

French authorities have also warned of a very high wildfire risk, as large fires in the south have already scorched thousands of hectares this week, disrupting the Tour de France cycling race and stretching firefighting resources.

The largest wildfire, which broke out in the eastern Pyrenees, near the Spanish border, has decreased in intensity, authorities said Friday.

It burned about 5,000 hectares (12,000 acres) and forced the evacuation of more than 10,000 people from nearly villages, who have since been allowed to return home.

Last month was France’s hottest June on record, with deaths surging by nearly a third during the hottest week.

Scientists warn that climate change caused in part by the burning of fuels like gasoline, oil and coal is exacerbating the frequency and intensity of heat and dryness, making certain regions more vulnerable to wildfires.

Spain is no stranger to wildfires, with last year's fire season burning more than 393,000 hectares (almost 1,520 square miles), according to the European Forest Fire Information System, an area twice as large as London. Four people died.

In 2017, a wildfire in neighboring Portugal left 66 people dead in Pedrogao Grande, located 200 kilometers (120 miles) northeast of Lisbon.

In that blaze, 47 people died on one road while similarly attempting to flee in their cars.

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Associated Press journalist Sylvie Corbet, in Paris, contributed.

A Military Emergency Unit vehicle operates as a wildfire rages in Alfajir, near Almeria in southeastern Spain, Friday, July 10, 2026. (AP Photo/Gregorio Marrero)

A wildfire rages in Alfajir, near Almeria in southeastern Spain, Friday, July 10, 2026. (AP Photo/Gregorio Marrero)

A wildfire rages in Alfajir, near Almeria in southeastern Spain, Friday, July 10, 2026. (AP Photo/Gregorio Marrero)