icecaps-in-antarctica-

Briefing on Arctic & Antarctic sea ice - August 2026

Alex West and Ed Blockley - 3rd August 2026

Summary

  • Arctic sea ice extent is currently 9th lowest on record for the time of year, at 7.02 million sq km on 2nd August
  • Extent was exceptionally low in the Kara Sea, and well below average in the remainder of the marginal seas bordering the Atlantic Ocean as well as the Siberian coastal seas
  • Arctic Ocean weather in July continued to be stormy and cyclonic, but temperatures were more widely above average than during June
  • September Arctic sea ice extent remains uncertain, but there is not yet any indication of a value either extremely high or extremely low relative to the post-2007 range
  • Antarctic sea ice extent is currently 5th lowest on record for the time of year, at 16.65 million sq km on 2nd August
  • Extent was somewhat below average across roughly half the Southern Ocean, spanning from the Weddell Sea to the Indian Ocean sector, but was more variable elsewhere with some regions of near- or above-average extent
  • July in the Antarctic continued the theme of lower pressure and strengthened westerly winds in the Southern Ocean, but with much higher pressure in the Amundsen Sea

Arctic

Sea ice state

Arctic sea ice extent on 2nd August 2026 was 7.02 million sq km according to the OSI SAF Sea Ice Index (Lavergne et al., 2023). This was the 9th lowest extent for the time of year in the satellite record (since 1979), the lowest having been 6.30 million sq km in 2020. It was 1.38 million sq km below the 1981-2010 average (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).

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 low in the Kara Sea. It was also well below average along the Atlantic Ocean ice edge in the Greenland Sea, Fram Strait, Barents Sea, and in the Laptev and East Siberian Seas north of Siberia, but near-average in the Beaufort and Chukchi Seas (Figure 2).

Figure 2. Arctic sea ice extent on 2nd August 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).

July in context

Average Arctic sea ice extent for July 2026 was, at 8.29 million sq km, the joint 5th lowest on record for the month (according to the OSI SAF Sea Ice Index), the lowest having been 7.91 million sq km in 2020. It was 1.55 million sq km below the 1981-2010 average, and close to the long-term linear trend (Figure 3). The average rate of sea ice loss for the month was 86,000 sq km per day, somewhat above the 1981-2010 average of 80,000 sq km per day.

Figure 3. Time series of July 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

Figure 3. Time series of July 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.

July was very stormy and unsettled over the Arctic Ocean (Figure 4a), much like the previous month. However, unlike in June many storms formed further south over Siberia before moving north into the Arctic, dragging repeated warm air outbreaks into the Laptev and East Siberian Seas, assisted by a persistent high-pressure ridge over northeast Asia.  This is borne out by the upper air temperature anomaly map for the month (Figure 4b), which shows much weaker cold temperature anomalies than in June, more restricted to the American side of the Arctic, with strong warm anomalies now extending throughout the Siberian coastal seas.

Figure 4. July 1st-28th 2026 anomaly relative to the 1981-2010 average in (a) sea level pressure; (b) 925 hPa temperature over the Arctic. Sea level pressure and temperature data are from the ERA5 reanalysis (Hersbach et al., 2017).

Figure 4. July 1st-28th 2026 anomaly relative to the 1981-2010 average in (a) sea level pressure; (b) 925 hPa temperature over the Arctic. Sea level pressure and temperature data are from the ERA5 reanalysis (Hersbach et al., 2017). The 925 hPa temperature represents conditions around 800 m 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

Arctic sea ice typically attains its minimum extent of the year in the month of September. The 2026 September sea ice extent remains highly uncertain, as the average rate of melt during August varies greatly from year-to-year and is very dependent on unpredictable Arctic weather patterns. However, the September sea ice extent is very likely to fall within the post-2007 range of values (3.99 to 5.68 million sq km), which is lower than and separate to the pre-2007 range (5.71 to 8.25 million sq km).

We make two statistical predictions of the range of September sea ice extents that remain likely given the current state of the ice. Firstly, adding trajectories of melt rate observed from 2007-2025 to the current sea ice extent suggests a range from 3.98 to 5.45 million sq km. Secondly, correlating detrended anomalies in sea ice extent from 19th July – 2nd August with September average values gives a very similar range, from 4.05 to 5.39 million sq km. Both predictions suggest that a September extent at either the top or the bottom of the post-2007 range would still represent an extreme outcome given the current state of the ice, with an intermediate value similar to that of the past few years perhaps more likely.

Figure 5. 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.

Figure 5. 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 2nd August was 16.65 million sq km. This was the 4th lowest extent for the time of year in the satellite record, the lowest having been 15.22 million sq km in 2023. It was 0.83 million sq km below the 1981-2010 average (Figure 6).

Figure 6. 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).

Figure 6. 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 somewhat below average across a wide swathe of the Southern Ocean stretching nearly halfway around the continent, from the edges of the Weddell Sea across the whole Indian Ocean sector. Extent was also below average in parts of the Ross and Amundsen Seas, and near the Antarctic Peninsula, but was near or above average in other areas (Figure 7).

Figure 7. Antarctic sea ice extent on 2nd August 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).

Figure 7. Antarctic sea ice extent on 2nd August 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).

July in context

The average Antarctic sea ice extent for July 2026 was 15.39 million sq km. This was the 5th-lowest July extent in the satellite record (since 1979), the lowest having been 13.99 million sq km in 2023. It was 0.94 million sq km below the 1981-2010 average. The average rate of ice gain during July was 76,000 sq km per day, somewhat faster than the 1981-2010 average rate of 72,000 sq km per day.

July 2026, like the previous month, was characterised by a strongly positive phase of the Southern Annular Mode (SAM), with lower-than-average pressure over Antarctica leading to enhanced westerly winds around the continent. The position of the strongest low-pressure anomalies was different to that in June, with much higher pressure over the Amundsen Sea and lower pressure over the Weddell Sea and the region west of the Ross Sea, south of Australia. These are associated with the El Niño climate pattern, characterised by warm sea surface temperatures in the tropical Pacific Ocean, which began developing in the spring of 2026. El Niño is thought to be linked to higher pressure over the Amundsen Sea, and together with the positive phase of the SAM may cause sea ice conditions to be closer to average over a large region of the Southern Ocean near the Antarctic Peninsula (Wang et al., 2023).

Figure 8. July 1st-28th 2026 anomaly relative to the 1981-2010 average in (a) sea level pressure; (b) 925 hPa temperature over the Southern Ocean. Sea level pressure and temperature data are from the ERA5 reanalysis (Hersbach et al., 2017). The 925 hPa temperature represents conditions around 800 m 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.

Figure 8. July 1st-28th 2026 anomaly relative to the 1981-2010 average in (a) sea level pressure; (b) 925 hPa temperature over the Southern Ocean. Sea level pressure and temperature data are from the ERA5 reanalysis (Hersbach et al., 2017). The 925 hPa temperature represents conditions around 800 m 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: 03-08-2026.

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: 03-08-2026.

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: 03-08-2026.

Wang, J., H. Luo, L. Yu, X. Li, P. R. Holland and Q. Yang (2023) The Impacts of Combined SAM and ENSO on Seasonal Antarctic Sea Ice Changes. J. Climate, 36, 3553-3569. https://doi.org/10.1175/JCLI-D-22-0679.1.

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