Antarctica experienced an extreme June heatwave, with temperatures soaring up to 15°C above normal, according to scientists at the UK's Rothera Research Station. Long-term records indicate that while typical winter temperatures average between -15°C and -20°C, last week readings reached around -2°C. Earlier this month, the station saw conditions more akin to summer, including rainfall and surface ice replacing heavy snowfall, alongside exceptionally low sea-ice levels.
Nearly 50 Years of Observations Show Clear Shift
Nearly 50 years of continuous monitoring at Rothera reveal a clear shift in winter conditions. Preliminary analysis suggests June 2025 was the warmest June on record since monitoring began in the late 1970s, and early indications point to June 2026 ranking among the warmest. The findings are part of a rapid-analysis study published this week by the British Antarctic Survey (BAS), concluding that the Antarctic Peninsula heatwave was amplified by human-driven climate change.
Human-Driven Climate Change Amplifies Heatwave
The study, part of the ExtAnt project led by BAS, examines extreme weather impacts on Antarctica and highlights how climate change increases the likelihood and intensity of such events. The changes extend beyond temperature: sea ice in the Bellingshausen Sea, west of the Antarctic Peninsula, has been in long-term decline. This year marks the third time in four years that Rothera has experienced no sea ice at midwinter. Across the continent, Antarctic sea-ice extent has remained well below average in recent years.
Consequences of Reduced Sea Ice
Scientists warn that reduced sea ice has significant consequences. Sea ice acts as a buffer between the ocean and atmosphere, shielding the Antarctic coastline from storms. When that barrier is diminished, warmer, moisture-laden air from lower latitudes can more easily reach the continent, bringing rainfall, winter heatwaves, and accelerating snow and ice loss.
Dr Tracy Moffat-Griffin, head of the Atmosphere, Ice and Climate team at BAS, said: 'While Antarctica remains one of the harshest environments on Earth, long-term records show that cold winter extremes around Rothera are becoming less common. Climate projections suggest this trend is likely to continue, with future winters characterised by fewer prolonged cold periods and more frequent warm events. It is an extremely worrying trend.'
Valuable Long-Term Records
Because Antarctic weather varies naturally from week to week, detecting long-term climate change requires decades of consistent observations. As BAS approaches 50 years of continuous monitoring at Rothera, the station's records are becoming an increasingly valuable tool for understanding how the Antarctic Peninsula is responding to a warming climate and what these changes may mean for future scientific operations.
