Arctic and Antarctic sea-ice information in January 2026

Arctic Sea Ice Information Monthly Report on Arctic Sea Ice

February 9, 2026

1. Arctic Sea Ice Conditions in January 2026

In January 2026, daily Arctic sea-ice extent ^{(note 1)} remained above the 2025 record low in early January, reached a minimum in mid-month, and then increased toward the end of the month (Figure 1). However, overall conditions remained persistently low. As a result, Arctic sea-ice extent in January 2026 averaged 12.63 million square kilometers, the third-lowest in the 48-year satellite record since 1979 (Figure 2). The sea-ice extent remained low in the Barents Sea and the Baffin Bay–Labrador Sea regions, particularly off the west coast of Greenland, where large open-water areas are found (Figure 3). Lower ice concentration was also found in the Sea of Okhotsk and the western Bering Sea. These conditions were partly associated with unusually warm atmospheric patterns (Figure 4). Air temperatures over the Baffin Bay region were 4–10°C above average, accompanied by warm southeasterly winds. Similar warm conditions (2–4°C) and inshore winds were observed over the Sea of Okhotsk. By contrast, colder-than-average temperatures persisted over parts of the Chukchi–Beaufort regions, northern Canada, and inland Russia.

Figure 1: Arctic sea-ice extent from November 1, 2025, to February 1, 2026 (red), compared with the previous 47 years (from November 1 to March 31). The 2012–2013 period is shown in black, the 2024–2025 period in yellow, and other years as thin lines. The 2010s (2011–2019) mean is indicated by the black dashed line. Here, sea-ice extent was calculated using a five-day average.

Figure 2: Interannual variability in January mean Arctic sea-ice extent from 1979 to 2026. Years with insufficient data to calculate monthly means (1979–1980, 1982, 1984–1985, and 1987) were treated as missing sea-ice extent.

Figure 3: Arctic sea-ice extent (a) and concentration (b) averaged in January 2026. The orange line indicates the sea-ice edge (area with at least 15% sea-ice concentration) averaged over the 2010s.

Figure 4: (a) Air temperature anomalies (°C) at the 925 hPa relative to the 2010s mean for January 2026. Yellow-to-red and light blue-to-dark blue shading indicate warmer and colder than the 2010s mean, respectively. (b) Sea level pressure (hPa) and wind vectors (m s^–1) at the 925 hPa for January 2026. Data from NCEP-NCAR Reanalysis 1 ^{(note 2)} is used in this figure.

2. Antarctic Sea Ice Conditions in January 2026

In January 2026, daily Antarctic sea-ice extent decreased steadily until early January, but after that, the rate of decline slowed and approached the 2010s mean (Figure 5). As a result, Antarctic sea-ice extent in January 2026 averaged 4.53 million square kilometers, which remained relatively high compared with recent years. This record is the 16th-lowest in the 48-year satellite record since 1979 (Figure 6). Rapid sea-ice loss was particularly apparent in the Riiser-Larsen Sea (Figure 7), likely due to low sea-ice concentration in the previous month ^{(note 3)}. Similar vulnerable conditions were also observed between the Ross and Amundsen Seas, suggesting the potential for accelerated melting under favorable weather conditions. In contrast, the Weddell Sea still has near-average sea-ice coverage and high ice concentration, which may have contributed to the slowdown in overall Antarctic sea-ice retreat.

Figure 5: Antarctic sea-ice extent from November 1, 2025, to February 1, 2026 (red), compared with the previous 47 years (from November 1 to March 31). The 2023–2024 period is shown in black, and other years are shown as thin lines. The 2010s (2011–2019) mean is indicated by the black dashed line. Here, sea-ice extent was calculated using a five-day average.

Figure 6: Interannual variability in January mean Antarctic sea-ice extent from 1979 to 2026. Years with insufficient data to calculate monthly means (1979–1980, 1982, 1984–1985, and 1987) were treated as missing sea-ice extent.

Figure 7: Antarctic sea-ice extent (a) and concentration (b) averaged in January 2026. The orange line indicates the sea-ice edge (area with at least 15% sea-ice concentration) averaged over the 2010s.

1: Sea-ice extent
For details on the calculation method of sea-ice extent, please refer to ADS . In this article, we used a five-day average.

2: NCEP-NCAR Reanalysis 1 (https://psl.noaa.gov/data/gridded/data.ncep.reanalysis.html) from Kalnay et al., The NCEP/NCAR 40-year reanalysis project, Bull. Amer. Meteor. Soc., 77, 437-470, 1996

3: Please refer to Arctic and Antarctic sea-ice information in December 2025 (in Japanese).