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Scientists from NASA and NOAA say the Antarctic ozone layer is showing signs of recovery. On September 9, it reached a maximum size of 8.83 million square miles — still large, but the fifth smallest ozone hole since 1992. The improvement is mainly due to the Montreal Protocol, which phased out ozone-destroying chemicals.
Researchers expect the ozone layer to fully recover later this century if current trends continue. Paul Newman of NASA noted that ozone holes are now forming later, shrinking earlier, and are smaller than in the early 2000s.
The ozone hole over Antarctica is slowly recovering, according to @nasa & @noaa’s long-term record.
This year’s ozone hole was the 5th-smallest on record, reaching an annual maximum extent of 8.83 million square miles on Sept. 9, 2025. https://t.co/becxmD6aKl pic.twitter.com/4glMTeXlng
— NASA Earth (@NASAEarth) November 24, 2025
During this year’s depletion season (September 7 to October 13), the ozone hole averaged 7.23 million square miles and began breaking up nearly three weeks earlier than usual. NOAA’s Stephen Montzka said ozone-depleting substances have fallen by about one-third since their peak around 2000.
The ozone layer, 7–31 miles above Earth, shields life from harmful UV radiation. Newman added that without past reductions in chlorine levels, this year’s ozone hole would have been over a million square miles larger.
