Arctic Records Its Hottest Year in 125 years on Record 

Feature image: Surface air temperatures across the Arctic between October 2024 and September 2025 were the warmest recorded since 1900. Credit: NOAA. 

The Arctic has just experienced its hottest year on record, a critical climate milestone that scientists warn is already reshaping weather systems far beyond the polar region. According to the NOAA Arctic Report Card 2025, surface air temperatures across the Arctic between October 2024 and September 2025 were the highest observed since records began in 1900. The findings confirm that the Arctic is warming at more than twice the global average (with research also stating an average warming rate of four times the globe), reinforcing its role as an early warning system for planetary change. 

Key Developments 

• Record heat and rainfall: The past decade has been the warmest on record in the Arctic. Rainfall reached its highest level ever, with multiple seasons among the wettest observed. 

• Sea ice at historic lows: Winter sea ice fell to its lowest maximum extent on record, while summer ice continues a long-term decline. 

• Rapid ocean warming: Parts of the Arctic Ocean were up to 7°C warmer than average, driven by warmer Atlantic waters moving north and speeding up ice melt. 

• Ecosystems under pressure: Increased phytoplankton growth by up to 80% is reshaping marine food webs, disrupting fisheries and Indigenous subsistence systems. 

• Accelerating ice loss: Glaciers in Scandinavia and Svalbard recorded their largest annual ice losses, while the Greenland Ice Sheet lost an estimated 129 billion tonnes of ice in 2025, contributing to sea level rise. 

• Polluted rivers: Thawing permafrost has released iron and other metals into over 200 Arctic watersheds, degrading water quality and threatening aquatic ecosystems. 

• Rapid land change: June snow cover across the Arctic is now about 50% lower than six decades ago, while tundra greenness ranks among the highest levels on record. 

Climate Change Context 

These changes are driven primarily by human-caused climate change, resulting from the burning of fossil fuels, deforestation, and other industrial activities that release heat-trapping greenhouse gases into the atmosphere. The Arctic is warming faster than the rest of the planet due to Arctic amplification, a process in which rising temperatures melt ice and snow that would normally reflect sunlight back into space. As darker ocean and land surfaces are exposed, more heat is absorbed, further accelerating warming. 

Human-driven warming is also intensifying the Arctic’s water cycle. More precipitation is falling as rain instead of snow, while warming oceans are altering atmospheric circulation and ocean currents. These changes weaken natural climate regulators, such as sea ice and cold ocean layers, linking Arctic warming directly to disruptions in the global climate system. 

Global Implications 

• More extreme weather: Arctic warming disrupts global weather systems, increasing heatwaves, floods, droughts, and cold spells across Europe, North America, and Asia. 

• Rising sea levels: Melting Arctic ice is contributing to sea-level rise, threatening coastal cities, ecosystems, and freshwater supplies worldwide. 

• Food security risks: Changes in ocean and land ecosystems affect fisheries and food production far beyond the Arctic. 

• Water stress: Altered rainfall, river systems, and permafrost thaw reduce both the quality and availability of freshwater. 

• Growing health threats: Warmer conditions and ecosystem shifts increase the spread of infectious diseases into new regions. 

Urgent Response Needed 

The Arctic Report Card underscores the systemic and escalating nature of polar change. Immediate global climate action strengthened polar monitoring, and integration of Indigenous knowledge and community-led observations are essential to understand, adapt to, and mitigate cascading impacts on ecosystems, human health, and societies. 

Read more: Extreme weather events | Health risks | Climate Risks Daily 

Original source: https://arctic.noaa.gov/report-card/report-card-2025/