PHOENIX — Extreme heat spread across Arizona, New Mexico and parts of Texas, Colorado and Kansas as severe weather swept across many parts of the U.S. on Sunday. There was unseasonable cold in the Pacific Northwest, snow headed to the northern Rocky Mountains, and heavy rainfall forecast from the northern Plains to the Upper Midwest.

The National Weather Service estimated that more than 63 million people were under heat advisories, stretching from the Southwest northward up through Denver and into Chicago.

Temperatures in Phoenix, which hit 112 degrees Fahrenheit (44.4 Celsius) on Saturday, were expected to reach close to that on Sunday. Weather service forecasters say the first two weeks of June in Phoenix already have been an average of 5.6 degrees Fahrenheit hotter than normal, making it the hottest start to June on record.

“We have already seen some pretty significantly high temperatures in our area,” said Ted Whittock, a meteorologist with the National Weather Service in Phoenix. “We are recommending that everyone reduce their time outdoors between 10 a.m. and 6 p.m., stay hydrated and wear light, looser fitting clothing.”

Whittock said the heat in metro Phoenix will ease a bit Monday through Wednesday, with the highs pushing back up as the week progresses, likely prompting another excessive heat warning.

Panda diplomacy: Chinese Premier Li Qiang promised a new pair of giant pandas Sunday to a zoo and urged Australia to set aside its differences with Beijing at the outset of the first visit to the country by China’s second-highest ranking leader in seven years.

China’s most powerful politician after President Xi Jinping arrived late Saturday in Adelaide.

Li’s trip has focused so far on the panda diplomacy, rebounding trade including wine and recovering diplomatic links after China initiated a reset of the relationship in 2022 that had all but collapsed during Australia’s previous conservative administration’s nine years in power.

Relations tumbled over legislation that banned covert foreign interference in Australian politics, the exclusion of Chinese-owned telecommunications giant Huawei from rolling out the national 5G network because of security concerns, and Australia’s call for an independent investigation into the causes of and responses to the COVID-19 pandemic.

Beijing imposed an array of official and unofficial trade blocks in 2020 on a range of Australian exports including coal, wine, beef, barley and wood that cost up to $13 billion a year.

All the trade bans have now been lifted except for Australian live lobster exports.

Foreign Minister Penny Wong said: “We will cooperate where we can, we will disagree where we must and we will engage in our national interest.”

Wong then joined Li at Adelaide Zoo, which has been home to China-born giant pandas Wang Wang and Fu Ni since 2009.

Li announced that the zoo would be loaned another two pandas after the pair are due to return to China in November.

California wildfire: Strong winds pushed flames through dry brush in mountains along Interstate 5 north of Los Angeles on Sunday, and officials warned residents in the wildfire’s path to be prepared to leave if it explodes in size again.

Los Angeles County’s first major wildfire of the year swiftly grew to more than 19 square miles, one day after it forced the evacuation of at least 1,200 campers, off-roaders and hikers from the Hungry Valley recreation area.

The blaze, dubbed the Post Fire, was just 2% contained. No injuries were reported. The cause is under investigation.

Firefighters working in sweltering conditions and steep terrain raced to douse spot fires that erupted as unpredictable winds blew embers ahead of the flames, said Kenichi Haskett, a section chief for the LA County Fire Department. The gusts also hampered efforts by aircraft crews to drop water and fire retardant.

“When it’s windy, it just sprays the water everywhere we don’t need it. So that’s a challenge,” Haskett said.

The fire erupted Saturday afternoon near I-5 in Gorman, about 60 miles northwest of Los Angeles. Two structures burned within the evacuated recreation area.

Tourist dies in Greece: A missing American tourist has been found dead on a beach on a small Greek island west of Corfu, local media reported.

The body of the man was found Sunday on a rocky, fairly remote beach on the island of Mathraki by another tourist. He had been reported missing Thursday by his host, a Greek-American friend.

The tourist had last been seen Tuesday at a cafe in the company of two female tourists who have since left the island.

No further details about the victim, including a name or hometown, were immediately available.

Mathraki, which has a population of 100, is a 1.2-square-mile wooded island, west of the better-known island of Corfu.

This was the latest in a string of recent cases in which tourists on the Greek islands have died or gone missing. Some, if not all, had set out on hikes in very high temperatures.

A 74-year-old Dutch tourist was found by a fire department drone Saturday lying face down in a ravine about 330 yards from the spot where he was last observed last Sunday, walking with some difficulty in the blistering heat.

Russia prison unrest: Security forces stormed a detention center in southern Russia on Sunday, killing inmates accused of links to the Islamic State group who had taken two staff members hostage, state-funded news channel RT reported.

Journalists on the scene reported the sounds of gunfire, while multiple ambulances were seen arriving at the prison in footage on social media.

The hostages at the pretrial detention center in Rostov-on-Don were uninjured, Russia’s Federal Penitentiary Service said in a statement. It said the hostage-takers had been “liquidated” but didn’t comment further. A number of local news outlets reported that at least some of the prisoners had been killed.

Singapore oil spill: An oil spill caused by a dredger boat hitting a stationary cargo tanker has blackened part of Singapore’s southern coastline, including the popular resort island of Sentosa, and sparked concerns of threatening marine wildlife as cleanup was underway Sunday.

The Netherlands-flagged dredger Vox Maxima struck the Singaporean fuel supply ship Marine Honor on Friday.

Singapore said late Saturday the leak from the vessel had been contained.