DOI: 10.25923/cj60-9s07

T. J. Ballinger¹, A. Crawford², M. C. Serreze³, S. Bigalke⁴, J. E. Walsh¹, B. Brettschneider⁵, R. L. Thoman^1,6, U. S. Bhatt⁷, E. Hanna⁸, H. Motrøen Gjelten⁹, S. -J. Kim¹⁰, J. E. Overland¹¹, and M. Wang^11,12

¹International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, AK, USA
²Department of Environment and Geography, University of Manitoba, Winnipeg, MB, Canada
³National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, USA
⁴Department of Geography, Portland State University, Portland, OR, USA
⁵National Weather Service Alaska Region, NOAA, Anchorage, AK, USA
⁶Alaska Center for Climate Assessment and Preparedness, University of Alaska Fairbanks, Fairbanks, AK, USA
⁷Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, USA
⁸Department of Geography and Lincoln Climate Research Group, University of Lincoln, Lincoln, UK
⁹Norwegian Meteorological Institute, Oslo, Norway
¹⁰Korea Polar Research Institute, Incheon, Republic of Korea
¹¹Pacific Marine Environmental Laboratory, NOAA, Seattle, WA, USA
¹²Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington, Seattle, WA, USA

Headlines

• Dating back to 1900, the Arctic experienced the warmest water year (October 2024-September 2025) and autumn (2024) on record.
• Since 2006, Arctic autumn and winter air temperatures have each increased by more than twice the corresponding increases in global air temperatures.
• Amplified Arctic warming has cascading impacts on the Arctic system, including glacial melt, sea ice decline, greening landscapes, and various ecological changes.

Overview

Pan-Arctic (60° N-90° N) surface air temperatures continue to increase faster than those for the planet as a whole (90° S-90° N), especially during winter (Ballinger et al. 2025). Since 1980, the Arctic annual air temperatures have warmed nearly three times faster than the global mean due to global anthropogenic greenhouse gas emissions (Sweeney et al. 2023; Zhou et al. 2024). This amplified Arctic warming has been linked with a plethora of ongoing and emerging physical and ecological changes that profoundly affect transportation, infrastructure, and subsistence livelihoods for many people across the Arctic with impacts extending to societies in lower latitudes (Moon et al. 2019; Walsh et al. 2020). Some widespread responses to this warming include increased annual precipitation (see essay Precipitation), increased greening of Arctic landscapes (see essay Tundra Greenness), and sustained mass loss of the Greenland Ice Sheet (see essay Greenland Ice Sheet) and Arctic glaciers and ice caps (see essay Glaciers and Ice Caps outside Greenland). Increased winter temperatures affect the development and thickening of sea ice across the Arctic marginal seas (see essay Sea Ice), while increasing summer temperatures are associated with more frequent and devastating high-latitude wildland fires across much of Alaska (York et al. 2020) and northern Canada (Jain et al. 2024). Surface air temperature observations from weather stations often provide localized, long-term records, which are augmented by atmospheric reanalyses to provide a more complete spatial representation of multidecadal Arctic change.

Consistent with previous Arctic Report Cards, the sections that follow examine this past year’s Arctic surface air temperatures in an historical context. For this year’s 20th anniversary issue of the Arctic Report Card, we also compare recent Arctic air temperature changes since 2006 against global rates of change. We subsequently highlight seasonal surface air temperature anomaly patterns and extremes and discuss associated large-scale atmospheric circulation patterns.

Annual and seasonal air temperatures in context

Annual air temperatures are averaged for the water year (i.e., October 2024-September 2025 represents 2025), while three-month seasons are referenced as follows: autumn 2024 (October-December [OND]), winter (January-March [JFM]), spring (April-June [AMJ]), and summer 2025 (July-September [JAS]).

Annual Arctic and global surface air temperature anomalies (i.e., differences from average temperature; see Methods and data) are shown in Fig. 1a. This past year was the warmest on record since 1900 with anomalies of 1.60°C above the 1991-2020 mean. Arctic temperature anomalies continue to be larger than those measured at the global scale. This is the 12th consecutive year where pan-Arctic temperature departures were above the global average. The years 2016-25 have been the Arctic’s warmest ten individual years on record, punctuated by several new annual and seasonal records (Fig. 2).

Arctic seasonal temperature anomalies during the past year were strikingly high (Fig. 1b-e). Autumn 2024 was the warmest on record since 1900 at 2.28°C above the 1991-2020 mean, while the winter and summer 2025 temperatures were the second and third warmest on record at 2.41°C and 0.83°C, respectively, above the 30-year average. Spring air temperatures were also elevated and ranked eighth warmest at 0.57°C above the 1991-2020 mean. Since the inception of the Arctic Report Card, the rates of annual and seasonal Arctic warming continue to exceed those of global warming. Most notably, from 2006 onward, autumn (0.77°C/decade versus 0.33°C/decade) and winter temperatures (0.87°C/decade versus 0.35°C/decade) have increased at rates more than double the corresponding global rates.

Several mechanisms and feedbacks underlie the ongoing Arctic warming pattern and explain why it has outpaced the global warming trend. For example, the water vapor feedback, whereby more water vapor from enhanced evaporation leads to higher longwave radiation at the surface, and northward heat and moisture transport from weather patterns contribute to year-round warm extremes (Cohen et al. 2020). In autumn and winter, when Arctic Amplification is strongest, Arctic Ocean heat accumulated from increased solar energy absorption amid summer sea-ice losses (see essay Sea Ice) and poleward advection of warm sub-Arctic water masses (see essay Atlantification) is released to the overlying atmosphere, driving warmer air temperatures. Patterns of seasonal air temperature anomalies, summarized below, align with some of these processes that drive Arctic climate change.

Seasonal air temperature anomaly patterns

Seasonal air temperature anomaly patterns are illustrated in Fig. 2. Autumn 2024 was characterized by positive temperature anomalies over most high latitude land and ocean areas except for the Chukchi Sea, Greenland Sea, Norwegian Sea, and Greenland (Fig. 2a). Record-high seasonal temperatures since 1940 (with anomalies of 4-6°C above the mean) were found around Hudson Bay, the Canadian Arctic Archipelago, Lincoln Sea, central Arctic Ocean, and in central Siberia. The extreme Hudson Bay temperatures during autumn 2024 were largely the result of record early sea ice retreat in eastern Hudson Bay that allowed for exceptional ocean heat uptake and supported a season-long marine heatwave (Soriot et al. 2025). Sea-level pressure (SLP) was anomalously high over Greenland and Iceland, yet anomalously low over the Barents Sea and Kara Sea (Fig. 3a), which supported the wet and cold versus dry and warm dipole in the North Atlantic Arctic (see essay Precipitation). Of note, the high SLP over Greenland and Iceland corresponded with a record-high September to November average value (1.78) of the Greenland Blocking Index, a measure of mid-tropospheric air pressure, since 1948 (Hanna et al. 2016, updated data). This high-pressure pattern supported warm air advection over areas of record warmth in the Canadian Arctic Archipelago and Lincoln Sea.

There were some similarities between air temperature patterns in autumn 2024 (Fig. 2a) and winter 2025 (Fig. 2b). Most notably, Canadian Arctic Archipelago record-high temperatures persisted into winter, while the Lincoln Sea, adjacent central Arctic Ocean, and central and eastern Eurasia remained warmer than average. The southern Barents Sea also saw record-high winter temperatures in 2025. During February, Svalbard was 6-8°C above the 1991-2020 climatology, which was the archipelago’s second warmest February since measurements began in the mid-1970s (Grinde et al. 2025). Much of the North Atlantic, from Baffin Bay to the Barents Sea, was anomalously warm, as was the southern Bering Sea and Alaska. The only areas of below-average temperatures were over the eastern Siberia and north central Canada. Much lower-than-average surface pressure indicative of an active storm track was found over eastern Canada (6-7 hPa), in contrast to above-average surface pressure south of Alaska and over northern Europe that supported southerly warm advection over those areas (Fig. 3b).

Spring 2025 was characterized by near-average air temperature patterns across the Arctic (Fig. 2c). Three regional exceptions were eastern Siberia and the Sea of Okhotsk, central Russia, and the Norwegian Sea, which saw record spring warmth. Central Greenland also saw above-average air temperatures during this time. Much of the Arctic saw below-average to near-average SLP conditions in spring (Fig. 3c).

Summer 2025 was characterized by average to above-average air temperatures over most Arctic lands, especially in the north central Siberian littoral zones (Fig. 2d). Record warmth characterized much of the North Atlantic high latitudes including central and eastern Greenland, the Norwegian Sea, northern Scandinavia, and areas northeast of Svalbard. Lower-than-normal SLP around Greenland and Iceland suggest an invigorated storm track may have contributed to the record warm North Atlantic Arctic summer (Fig. 3d).

Methods and data

The NASA Goddard Institute for Space Studies surface temperature analysis version 4 (GISTEMP v4) is used to describe long-term Arctic and Global surface (i.e., two-meter) air temperatures since 1900 (Fig. 1). GISTEMP v4 air temperatures over lands are obtained from the NOAA Global Historical Climatology Network version 4 (GHCN v4) dataset and ocean surface temperatures are taken from the NOAA Extended Reconstructed Sea Surface Temperature version 5 (ERSST v5) dataset. The GISTEMP product is described in Hansen et al. (2010) and Lenssen et al. (2019).

We use ERA5 two-meter (i.e., near-surface) air temperature and sea-level pressure fields in Figs. 2 and 3, respectively, to provide spatial context to recent Arctic temporal variability shown in Fig. 1. ERA5 provides consistency with other sections of the Arctic Report Card, including Precipitation. Details of ERA5 reanalysis are provided in Hersbach et al. (2020). All values and fields are presented as anomalies with respect to the 1991-2020 mean. Temperature changes, spanning the subscripted periods in each Fig. 1 panel, represent linear least squares trends per decade.

References

Ballinger, T. J., and Coauthors, 2025: Surface air temperature. [in “State of the Climate in 2024”]. Bull. Amer. Meteor. Soc., 106(8), S311-S313, https://doi.org/10.1175/BAMS-D-25-0104.1.

Cohen, J., and Coauthors, 2020: Divergent consensuses on Arctic amplification influence on midlatitude severe winter weather. Nat. Climate Change, 10, 20-29, https://doi.org/10.1038/s41558-019-0662-y.

Grinde, L., J. Mamen, K. Tunheim, and S. Aaboe, 2025: Været i Norge – Klimatologisk månedsoversikt februar 2025 [The weather in Norway – Climatological monthly overview February 2025]. MET info, 02-2025, Norwegian Meteorological Institute, https://www.met.no/publikasjoner/met-info.

Hanna, E., T. E. Cropper, R. J. Hall, and J. Cappelen, 2016: Greenland Blocking Index 1851-2015: a regional climate change signal. Int. J. Climatol., 36(15), 4847-4861. https://doi.org/10.1002/joc.4673.

Hansen, J., R. Ruedy, M. Sato, and K. Lo, 2010: Global surface temperature change. Rev. Geophys., 48, RG4004, https://doi.org/10.1029/2010RG000345.

Hersbach, H., and Coauthors, 2020: The ERA5 global reanalysis. Quart. J. Roy. Meteor. Soc., 146, 1999-2049, https://doi.org/10.1002/qj.3803.

Jain, P., and Coauthors, 2024: Drivers and impacts of the record-breaking 2023 wildfire season in Canada. Nat. Commun., 15, 6764, https://doi.org/10.1038/s41467-024-51154-7.

Lenssen, N. J. L., G. A. Schmidt, J. E. Hansen, M. J. Menne, A. Persin, R. Ruedy, and D. Zyss, 2019: Improvements in the GISTEMP uncertainty model. J. Geophys. Res.-Atmos., 124, 6307-6326, https://doi.org/10.1029/2018JD029522.

Moon, T. A., and Coauthors, 2019: The expanding footprint of rapid Arctic change. Earth’s Future, 7(3), 212-218, https://doi.org/10.1029/2018EF001088.

Soriot, C., J. Stroeve, and A. Crawford, 2025: Record early sea ice loss in southeastern Hudson Bay in Spring 2024. Geophys. Res. Lett., 52(4), e2024GL112584, https://doi.org/10.1029/2024GL112584.

Sweeney, A. J., Q. Fu, S. Po-Chedley, H. Wang, and M. Wang, 2023: Internal variability increased Arctic amplification during 1980-2022. Geophys. Res. Lett., 50, e2023GL106060, https://doi.org/10.1029/2023GL106060.

Thoman, R., 2025: Arctic summer 2025 climate summary. https://alaskaclimate.substack.com/p/arctic-summer-2025-climate-summary.

Walsh, J. E., T. J. Ballinger, E. S. Euskirchen, E. Hanna, J. Mård, J. E. Overland, H. Tangen, and T. Vihma, 2020: Extreme weather and climate events in northern areas: A review. Earth Sci. Rev., 209, 103324, https://doi.org/10.1016/j.earscirev.2020.103324.

York, A., U. S. Bhatt, E. Gargulinski, Z. Grabinski, P. Jain, A. Soja, R. L. Thoman, and R. Ziel, 2020: Wildland fire in high northern latitudes. Arctic Report Card 2020, R. L. Thoman, J. Richter-Menge, and M. L. Druckenmiller, Eds., https://doi.org/10.25923/2gef-3964.

Zhou, W., L. R. Leung, and J. Lu, 2024: Steady threefold Arctic amplification of externally forced warming masked by natural variability. Nat. Geosci., 17, 508-515, https://doi.org/10.1038/s41561-024-01441-1.

November 18, 2025