The American Geophysical Union Fall Meeting is in progress, it’s time for NOAA’s annual Arctic Report Card, which is always a high point of the meeting.
Summary video above, 3 minutes.
Excerpts from the Executive Summary below, much more at the link.
Arctic surface air temperatures during the past year (October 2024-September 2025; the annual period that aligns with the natural water cycle) were the highest on record since at least 1900. This included the Arctic experiencing its warmest autumn, second-warmest winter, and third-warmest summer since 1900, reinforcing the now well-established pattern of amplified regional warming. Over the past 20 years, Arctic autumn and winter air temperatures have each increased by more than twice the corresponding increases in global air temperatures.
An intensifying hydrologic cycle, driven by increased evaporation, precipitation, and meltwater production, continues to emerge as a central expression of persistent Arctic heating. The 2024/25 water year saw record-high precipitation averaged for the entire year and for spring, and ranked among the top five wettest years for all other seasons since 1950. These patterns are consistent with a more moisture-laden atmosphere and an increasing frequency of extreme precipitation events, including atmospheric rivers that can deliver heavy amounts of rain or snow to large regions. For example, an atmospheric river was responsible for heavy precipitation in the Aleutians and across Alaska in January 2025, contributing to an overall Arctic winter with more extreme precipitation events than any other season.
Snow cover on land is directly influenced by the observed increases in Arctic precipitation, while at the same time the reduction in snow cover duration amplifies Arctic warming. The year 2025 was a clear example of this, consistent with conditions over the last 15 years. While the winter snowpack was above average across much of the Arctic, rapid melting in late spring caused June snow extent to drop below normal, continuing a six-decade decline. June snow cover extent is now 50% of what it was in the 1960s, altering river discharge, vegetation processes, animal behavior, and fire risk. The loss of reflective snow surfaces in June, when incoming solar energy reaches its annual maximum, results in more heat absorbed at the surface, contributing to further Arctic warming trends.
The Arctic’s highly reflective surfaces are also diminishing in the ocean as sea ice cover shrinks. The annual maximum sea ice extent in March 2025 was the lowest in the 47-year satellite record, while the minimum ice extent in September was the 10th lowest. Compared with 2005—the year discussed in the first Arctic Report Card—the end-of-summer sea ice extent in 2025 was 28% smaller and considerably thinner and younger. Multi-year sea ice is now largely confined to the area north of Greenland and the Canadian Archipelago, and the thickest, oldest (> 4 years) ice has declined by more than 95% since the 1980s.
Loss of ice is also apparent on land. The Greenland Ice Sheet continued to lose mass in 2025, though the annual loss was less than the 2003-24 mean due to enhanced snowfall and below-average melt. However, the long-term trend remains consistent; Greenland continues to be a major contributor to global sea-level rise and a driver of freshwater and nutrient inputs that influence North Atlantic ocean circulation and marine productivity. Similarly, Arctic glaciers and ice caps outside of Greenland have rapidly thinned since the 1950s, also contributing steadily to rising global sea levels.
The warming of ocean waters is also extremely consequential to the Arctic region. August mean sea surface temperatures (SSTs) show warming trends during 1982-2025 in almost all Arctic Ocean regions that are ice-free in August, with increases of ~0.3°C (~0.54°F) per decade in the region north of 65° N. This warming alters ecosystems and is a prime driver of sea ice loss. In 2025, August SSTs in most Arctic regions ranked among the warmest on record. Yet, stark regional differences were observed. While the Atlantic sector of the Arctic Ocean was anomalously warm, with SSTs as high as 7°C (12.6°F) above the 1991-2020 average, the Beaufort and northern Chukchi Seas in the Pacific sector were 1-2°C (1.8-3.6°F) cooler than average.
- In Arctic Alaska, surface waters have changed from clear to orange in over 200 watersheds, with most changes occurring within the past decade. Evidence suggests this “rusting” is an emerging issue due to iron release from thawing permafrost soils.
- Rusting rivers have degraded water quality and habitat, with increased acidity and toxic trace metal concentrations contributing to a loss of aquatic biodiversity in headwater streams.
- Ongoing research aims to understand the causes and consequences of rusting rivers, particularly regarding impacts to drinking water supplies for rural communities and subsistence fisheries.
In a 2024 study, we reported on the emergence of 75 streams in Alaska’s Brooks Range that had turned from clear to orange (O’Donnell et al. 2024). Since then, we have compiled additional observations from more than 200 streams and rivers that are discolored (Fig. 1; Hill 2024). These rusting rivers are visually striking (Fig. 2a,c,e) and are readily detected using satellite imagery. Using historical satellite imagery, we showed that most of these streams have changed color in the past 10 years. This shift coincides with a dramatic increase in air and ground temperatures across the region, indicating that recent permafrost thaw is a likely driver (Swanson et al. 2021).