Three Argentine research stations on the Antarctic Peninsula logged record winter highs on June 5–6, with Esperanza reading 59.7°F, about 36°F above the seasonal norm, in a region warming roughly five times faster than the rest of the planet.
On June 6, 2026, instruments at Argentina's Esperanza base, at the tip of the Antarctic Peninsula, recorded 59.7°F (15.4°C), the highest winter temperature ever measured at the station. It surpassed the previous record of 57.1°F (14°C), set in 1998, by 3.6°F (2°C). The reading sat roughly 36°F (20°C) above the typical June temperature at the tip of the peninsula, in the season that should be Antarctica's most thermally stable.
The reading was not isolated. Two other Argentine research stations on the peninsula, Marambio and San Martín, logged their own record winter highs in the same June 5–6 window. Three independent, instrumented stations recorded unprecedented winter warmth within the same 48 hours, a pattern that transforms a single freak reading into a documented, corroborated event. The Argentine Antarctic Institute confirmed the figures, according to Gizmodo's report on the records.
The Antarctic Peninsula is not the interior of the continent. It is the long, narrow finger of land and islands that extends from the Antarctic landmass toward the southern tip of South America, and it has been warming faster than nearly anywhere else on Earth. Average temperatures on the peninsula have risen nearly 5.4°F (3°C) since 1950, roughly five times the global average over the same period. The June 6 reading sits inside that documented record, not above it. It is the most recent expression of a trend that has been measured for decades.
The physical mechanism behind the peninsula's outsize warming is a feedback loop. When sea ice retreats in winter, more dark ocean is exposed to the limited polar sunlight. The dark ocean absorbs more heat than the ice it replaced, the air above it warms, and that warmer air melts more ice. The cycle is called the sea-ice albedo feedback, and it has, in the source's framing, "supercharged" the peninsula's warming relative to the rest of the planet. The mechanism is plain: less reflective surface, more heat absorbed, more ice lost.
"This is absolutely crazy," Raúl Cordero, a climate scientist at the University of Groningen in the Netherlands, told The Guardian, according to Gizmodo's account of the reporting. The quote lands as confirmation, after the numbers and the trend have done their work. It is the exclamation a reader can earn, not the headline.
There are real limits to what the June 6 reading proves on its own. A single weather event is a measurement, not a verification of long-term climate dynamics, and the longer trend is what is documented, not this specific night. The Antarctic Peninsula is also a small share of the continent: the reading reflects conditions on the peninsula, not the interior plateau, and a reader who walked away thinking "Antarctica as a whole is warming five times faster than the planet" would be wrong, because the multiplier applies to the peninsula specifically.
What the three-station record does do is place the June 6 anomaly inside a region where the longer trend is already on the page. Esperanza's reading sat at a season when air temperatures at the tip of the peninsula normally hover around freezing or below. The 59.7°F reading was the upper bound of what Argentine instruments have ever measured there in winter, and it was reached on the same night that two sister stations broke their own previous winter highs. The climate of the Antarctic Peninsula has been changing for the better part of a century. The open question is how often this season's records get rewritten, and how fast.
Researchers have framed the June 5–6 window as part of a longer pattern of more severe heat events along the peninsula. The World Meteorological Organization has not, as of this writing, issued a formal statement on the June 2026 readings. Argentina's Servicio Meteorológico Nacional and the Argentine Antarctic Institute have confirmed the Esperanza, Marambio, and San Martín numbers.