Temperatures in Antarctica have risen by as much as 15°C above normal, with scientists at the UK's Rothera Research Station reporting conditions that are becoming increasingly unrecognisable. Long-term records show that while typical winter averages range between -15°C and -20°C, last week temperatures reached around -2°C.
Unprecedented winter warmth at Rothera
Earlier this month, Rothera experienced conditions more typical of summer than winter, with rainfall and surface ice replacing the heavy snowfall usually expected, alongside exceptionally low sea-ice levels. Nearly 50 years of observations at the station indicate a clear shift in winter conditions. Preliminary analysis suggests June 2025 was the warmest June recorded since monitoring began in the late 1970s, while early indications suggest June 2026 could also rank among the warmest on record.
Human-driven climate change amplifies heatwave
The findings form part of a broader rapid-analysis study published this week, involving British Antarctic Survey scientists, which concludes that a recent Antarctic Peninsula heatwave was amplified by human-driven climate change. The study, part of the ExtAnt project led by the British Antarctic Survey, examines the impacts of extreme weather on Antarctica and highlights how climate change is increasing both the likelihood and intensity of such events.
Sea ice decline and consequences
The changes are not limited to temperature. Sea ice in the Bellingshausen Sea, west of the Antarctic Peninsula, has been in long-term decline, and 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. Scientists say the reduction in sea ice has significant consequences. Sea ice acts as a buffer between the ocean and atmosphere, helping to shield the Antarctic coastline from storms. When that barrier is reduced, warmer, moisture-laden air from lower latitudes can more easily reach the continent, bringing rainfall, winter heatwaves and accelerating the loss of snow and ice.
Expert warns of worrying trend
Dr Tracy Moffat-Griffin, head of the Atmosphere, Ice and Climate team at the British Antarctic Survey, 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.'
Value of long-term monitoring
Because Antarctic weather naturally varies from week to week, detecting long-term climate change requires decades of consistent observations. As the British Antarctic Survey approaches 50 years of continuous monitoring at Rothera, scientists say 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.
