A powerful polar air mass has plunged Argentina, Chile, and Uruguay into record-breaking cold, resulting in at least 15 fatalities.
The extreme temperatures have forced governments to implement emergency measures, including gas supply restrictions and the opening of shelters to protect vulnerable populations, News.Az reports, citing AFP.
The three South American countries have all recorded sharply below-zero temperatures as the polar air originated from Antarctica and swept across the region.
In Argentina, at least nine homeless people have died from the cold this winter, according to NGO Proyecto 7.
The capital Buenos Aires recorded its lowest temperature since 1991 at -1.9 degrees Celcius (28.6 Fahrenheit) on Wednesday, while the coastal city of Miramar saw snow for the first time in 34 years. Further south, the town of Maquinchao recorded -18C on Tuesday.
Electricity demand caused cuts across Buenos Aires, leaving thousands without power for over 24 hours in some areas.
Uruguay declared a nationwide "red alert" after six people died, allowing President Yamandu Orsi's government to forcibly move homeless people to shelters.
Montevideo recorded its lowest maximum temperature since 1967 at 5.8C on June 30, according to meteorologist Mario Bidegain.
Chile also activated homeless shelter plans during the coldest days. The city of Chillan, 400 kilometers (250 miles) south of Santiago, hit -9.3C, according to the Chilean Meteorological Directorate.
"What happened this week in Chile and the Southern Cone in general is a cold wave caused by an escape of a polar air mass from Antarctica," climatologist Raul Cordero from the University of Santiago told AFP.
Snow even fell in parts of the Atacama Desert, the world's driest, for the first time in a decade.
"It is not so common for these cold air masses to extend so far north, so we cannot rule out that this is also caused by climate change," meteorologist Arnaldo Zuniga told AFP.
The region expects relief in the coming days, with Buenos Aires reaching 12C on Thursday, Montevideo 14C and Santiago 24.7C.
"I was quite surprised by the change from cold to hot -- the change was very drastic," student Dafne Naranjo, 18, said in Santiago.
Climatologist Cordero said heatwaves have become more frequent than cold spells in recent years.
"The frequency of heatwaves has tripled, whether in summer or winter, not only in the Southern Cone but throughout the world," he said.
The government suspended gas supplies to industries and petrol stations Wednesday to ensure household supplies, and removed price controls on gas cylinders Thursday.