A strong polar air mass originating from Antarctica swept across southern South America between June 30 and July 3, causing record low temperatures, at least 15 deaths, and widespread emergency measures in Argentina, Chile, and Uruguay.
In Argentina, the capital Buenos Aires recorded a minimum temperature of -1.9°C (28.6°F) on July 2, the lowest since 1991, while the coastal city of Miramar experienced snowfall for the first time in 34 years. The Patagonian town of Maquinchao registered -18°C (-0.4°F) on July 1.
According to Proyecto 7, a non-governmental organization, at least nine homeless individuals have died in Argentina this winter due to exposure. Increased electricity demand caused extended power outages across Buenos Aires, with some areas left without power for over 24 hours. On July 2, the government suspended gas supplies to industrial users and petrol stations to ensure household access, lifting price controls on gas cylinders on July 3.
Uruguay declared a nationwide red alert after six deaths were reported. Authorities forcibly relocated homeless people to emergency shelters. The capital Montevideo recorded a maximum temperature of 5.8°C (42.4°F) on June 30, the lowest since 1967. The government activated emergency protocols to safeguard vulnerable populations.
Chile also experienced sharp drops in temperature. The city of Chillán, located 400 km (250 miles) south of Santiago, reported -9.3°C (15.3°F), according to the Chilean Meteorological Directorate. Snow was observed in the Atacama Desert, the world’s driest region, for the first time in a decade. Chilean authorities implemented emergency shelter plans for homeless populations during the coldest period.
Climatologists attributed the cold wave to a rare northward movement of polar air from Antarctica. “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,” said Raul Cordero, climatologist at the University of Santiago.
By July 3, temperatures rebounded rapidly across the region: Buenos Aires reached 12°C (53.6°F), Montevideo 14°C (57.2°F), and Santiago 24.7°C (76.5°F). “I was quite surprised by the change from cold to hot, the change was very drastic,” a studend from Santiago told AFP.
