The 2023 Antarctic ozone hole reached its maximum size at 10 million square miles, or 26 million square kilometers, on Sept. 21, which ranks as the 16th largest since 1979, according to annual satellite and balloon-based measurements made by NASA and NOAA.
During the peak of the ozone depletion season from Sept. 7 to Oct. 13, the hole averaged 8.9 million square miles (23.1 million square kilometers), approximately the size of North America
