Updated
Updated · National Oceanic and Atmospheric Administration · Nov 4
Antarctic Ozone Hole Ranks 7th-Largest at 9.6 Million Square Miles as Polar Vortex Swells
Updated
Updated · National Oceanic and Atmospheric Administration · Nov 4

Antarctic Ozone Hole Ranks 7th-Largest at 9.6 Million Square Miles as Polar Vortex Swells

3 articles · Updated · National Oceanic and Atmospheric Administration · Nov 4

Summary

  • NOAA and NASA said the 2026 Antarctic ozone hole averaged 9.6 million square miles from Sept. 7 to Oct. 13, making it the seventh-largest in 48 years of records.
  • A powerful polar vortex drove the expansion by trapping unusually cold air over a wider area after weak August-September wave activity failed to disrupt the vortex.
  • The hole peaked at 10.5 million square miles on Sept. 18—about 90% of the 2000 record—while ozone over the South Pole fell to 105 Dobson units on Oct. 17, above the record low of 92 in 2006.
  • Scientists said the hole would have been 1 million to 2 million square miles larger without cuts in ozone-depleting chemicals under the 1987 Montreal Protocol.
  • Long-term recovery remains on track, with Antarctic stratospheric chlorine down about one-third from its peak and the ozone hole still expected to recover by the 2070s.

Insights

Is the unusually strong polar vortex that enlarged the 2026 ozone hole a mere weather anomaly, or a symptom of broader climate shifts?
Could natural halogens from oceans quietly delay the ozone layer's expected 2070s recovery despite the success of the Montreal Protocol?