Briefing on Arctic and Antarctic sea ice - July 2026

Summary

• Arctic sea ice extent is currently 4th lowest on record for the time of year at 9.07 million sq km on 8th July
• Extent is exceptionally low along the Atlantic sea ice edge and in many of the Atlantic marginal seas, but is nearer average across the rest of the Arctic Ocean
• June 2026 saw a near-average rate of ice retreat, but this was dominated by rapid retreat in the Atlantic seas, with very limited ice retreat in the rest of the Arctic Ocean
• June was exceptionally stormy over the Arctic Ocean. Persistent southerly winds produced warm temperatures in the Atlantic sector, but elsewhere temperatures were rather cool
• September Arctic sea ice extent remains difficult to predict as it is highly affected by weather during the rest of the summer, but a 2026 September extent in the post-2007 range (3.99 to 5.68 million sq km) is highly likely
• Antarctic sea ice extent is currently 6th lowest on record for the time of year at 14.70 million sq km on 8th July
• Extent is particularly low in the Bellingshausen Sea and western Weddell Sea next to the Antarctic Peninsula, and is also somewhat low in the Indian Ocean sector
• June 2026 saw very low pressure across the whole Southern Ocean, particularly in the Amundsen Sea, likely helping cause the warm temperatures and low sea ice conditions near the Antarctic Peninsula

Arctic

Sea ice state

Arctic sea ice extent on 8^th July was 9.07 million sq km according to the OSI SAF Sea Ice Index (Lavergne et al., 2023). This was 1.42 million sq km below the 1981-2010 average, and the 5^th lowest extent for this date in the satellite record (since 1979), the lowest having been 8.88 million sq km in 2020 (Figure 1).

Figure 1. Daily Arctic sea ice extent for 2026, compared with recent years, the notably low ice years of 2007 and 2012, and the 1981-2010 average, with interquartile and interdecile ranges indicated by the shaded areas. Data are from the OSI SAF Sea Ice Index (Lavergne et al., 2023).

Extent was exceptionally below average in the Barents and Kara Seas, and in Hudson and Baffin Bays. It was below average to a lesser extent in the Laptev and East Siberian Seas, and in the Greenland Sea and Fram Strait. Extent was near-average in the Beaufort and Chukchi Seas, with limited ice retreat in these areas at the time of writing (Figure 2).

Figure 2. Arctic sea ice extent on 8^th July 2026, with 1981-2010 average extent indicated in orange, and the regions referred to in the text labelled. Data are from EUMETSAT OSI SAF (Tonboe et al., 2017).

 June 2026 in context

Arctic sea ice extent for June 2026 was 10.85 million sq km. This was the 5^th lowest average June extent in the satellite record, and 1.00 million sq km below the 1981-2010 average (Figure 3).

Figure 3. Time series of June Arctic sea ice extent according to the OSI SAF Sea Ice Index (Lavergne et al., 2023), with 1981-2010 average and 1979-2024 linear trend indicated.

By contrast, the average rate of extent loss for the month was 102,000 sq km per day, which is near the 1981-2010 average of 99,000 sq km per day. Ice decrease during June was dominated by marginal seas such as Hudson Bay and Baffin Bay, and near the ice edge in the Atlantic Ocean, with very little ice loss in the rest of the Arctic Ocean; unusually, some coastal regions saw ice increase during the month (Figure 4).

Figure 4. Map of average rate of change of ice concentration during June 2026. Green areas indicate a decrease in ice cover, purple areas an increase in ice cover.

June 2026 was relentlessly cyclonic and stormy in the Arctic Ocean (Figure 5a); over the inner Arctic Ocean region, away from the coastal seas, the average sea level pressure was the lowest since 1979 according to the ERA5 reanalysis (Hersbach et al., 2017). Mostly, these storms were formed of cold air masses, developing over the Arctic Ocean itself rather than bringing up warmer air from midlatitude regions. Pressure was also often rather low over Greenland, except for a brief spell mid-month.

The Atlantic Ocean ice edge to the east of Greenland, in the Fram Strait, Barents Sea and Kara Sea, was the only part of the Arctic Ocean to see well-above average upper air temperatures during June. Across the rest of the Arctic Ocean, upper air temperatures were near- or well-below average (Figure 5b). The chilly, stormy weather of June may explain the rather limited retreat of ice in the Arctic Ocean away from the Atlantic ice edge, as storms can spread out sea ice, and are often associated with clouds that shield the ice from sunlight.

Figure 5. June 2026 anomaly relative to the 1981-2010 average in (a) sea level pressure; (b) 925hPa temperature. Sea level pressure and temperature data are from the ERA5 reanalysis (Hersbach et al., 2017). The 925hPa temperature represents conditions around 800m above sea level and shows the position of warm/cool airmasses more clearly than the surface temperature, which responds strongly to the sea ice cover itself.

Outlook for September

At this stage in the melt season the September Arctic sea ice extent remains very uncertain, as melting for the rest of the summer will still be heavily dependent on the evolution of Arctic weather conditions. However, it is very likely that this September’s Arctic sea ice extent will be lower than the pre-2007 record low (5.71 million sq km in 2005 according to the OSI SAF Sea Ice Index) as have all years since 2007.

To predict a plausible range of September Arctic ice extents that are possible this year, we use two simple methods. Firstly, applying the melting trajectories observed for each year from 2007-2024 to the current extent gives a range of plausible September extents of 4.04 to 5.57 million sq km. Secondly, there exists a significant correlation between ice extent for 24^th June – 8^th July and that for September; applying basic statistical methods to this relationship gives a September range of 3.74 to 5.51 million sq km. These ranges either approach or encompass potential new record lows (the current lowest September sea ice extent is 3.99 million sq km) but also September extent near the top of the post-2007 range.

Each summer, scientific institutes from around the world submit estimates of September Arctic sea ice extent in a report known as the Sea Ice Outlook, collated by the Sea Ice Prediction Network. Because the estimates are compared to the NSIDC Sea Ice Index, which measures slightly lower sea ice extents than the OSI SAF Index used in this report, an adjustment of +0.38 million sq km is applied when quoting the Sea Ice Outlook predictions here. In June, 18 estimates were submitted to the Outlook, ranging from 4.22 to 5.18 million sq km with a median of 4.83 million sq km; these would be consistent with a September extent in the range 2^nd to 13^th lowest.

The Sea Ice Outlook estimates, and statistical estimates described above, are displayed in Figure 6.

Figure 6. September Arctic sea ice extent since satellite records began in 1979 from the OSI SAF Sea Ice Index (Lavergne et al., 2023) with statistical predictions for September 2026. For the statistical prediction derived from linear fit, error bars represent twice the standard deviation of September mean ice extent about the trend lines with respect to which the estimates are taken. The range of predictions derived from past melting trajectories is shown as a red boxplot indicating range, median and quartiles of estimates derived from all trajectories in the 2007-2024 period.

Antarctic

Sea ice state

Antarctic sea ice extent on 8^th July was 14.70 million sq km. This was 1.02 million sq km below the 1981-2010 average, and the 4^th lowest on record for the date, the lowest having been 13.26 million sq km in 2023 (Figure 7).

Figure 7. Daily Antarctic sea ice extent for 2026, compared with recent years, selected historic years with relatively low ice cover, and the 1981-2010 average, with interquartile and interdecile ranges indicated by the shaded areas. Data are from the OSI SAF Sea Ice Index (Lavergne et al., 2023).

Extent was well below average in the Bellingshausen Sea and Indian Ocean sector, as well as parts of the Weddell Sea, but was near-average elsewhere and slightly above average between the Ross and Amundsen Seas (Figure 8).

Figure 8. Antarctic sea ice extent on 8^th July 2026, with 1981-2010 average extent indicated in orange, and the regions referred to in the text labelled. Data are from EUMETSAT OSI SAF (Tonboe et al., 2017).

 June 2026 in context

June 2026 saw a strongly positive phase of the Southern Annular Mode, characterised by lower-than-normal pressure over the Southern Ocean near Antarctica, and higher-than-normal pressure in the Southern Hemisphere midlatitudes (Figure 9a). This pressure pattern enhances the strength of the westerly winds that circle the Southern Ocean and is particularly associated with warm and wet conditions in and around the Antarctic Peninsula (e.g., Marshall and Thompson, 2016). In addition, the Amundsen Sea Low was stronger than normal, causing cold southerly winds to its west, over the Ross Sea, and warm northerly winds to its east, over the Bellingshausen Sea, explaining the temperature anomalies in these regions (Figure 9b).

Figure 9. June 2026 anomaly relative to the 1981-2010 average in (a) sea level pressure (b) 925hPa temperature. Sea level pressure and temperature data are from the ERA5 reanalysis (Hersbach et al., 2017). The 925hPa temperature represents conditions around 800m above sea level and shows the position of warm/cool airmasses more clearly than the surface temperature, which responds strongly to the sea ice cover itself.

References

Hersbach, H. et al. (2017) Complete ERA5 from 1940: Fifth generation of ECMWF atmospheric reanalyses of the global climate. Copernicus Climate Change Service (C3S) Data Store (CDS). https://doi.org/10.24381/cds.143582cf. Date Accessed: 09-07-2026.

Lavergne, T. et al. (2023) OSI SAF Sea ice index 1978-onwards, Product OSI-420, Version 2.2, May 2023, Available at: https://thredds.met.no/thredds/osisaf/osisaf_seaiceindex.html. Date Accessed: 09-07-2026.

Marshall, G. J., and D. W. J. Thompson (2016), The signatures of large-scale patterns of atmospheric variability in Antarctic surface temperatures, J. Geophys. Res. Atmos., 121, 3276-3289. https://doi.org/10.1002/2015JD024665.

Tonboe, R., J. Lavelle, R.-H. Pfeiffer and E. Howe (2017) OSI SAF Global Sea Ice Concentration, Product OSI-401-b, Version 1.6, September 2017. Available at: https://osi-saf.eumetsat.int/products/osi-401-b. Date Accessed: 09-07-2026.