The Antarctic ozone hole in 2025 was one of the smallest in decades - testimony to the continuing success of international action to protect the Earth's ozone layer which shields us against the sun's harmful ultraviolet rays, according to a new report from the World Meteorological Organization (WMO).
In welcome news, the WMO Ozone Bulletin said that last year's ozone hole ranked as the fourth to fifth smallest since severe depletion patterns were observed in 1992. This is the second consecutive year that both the depth and extent of the ozone hole were significantly below the 1990-2010 average.
ear-to-year fluctuations are influenced by large-scale meteorological transport conditions which drive springtime ozone depletion, an event that occurs after almost every austral winter above Antarctica, and every 5 to 10 years in the northern hemisphere.
In the Northern Hemisphere, total column ozone in 2025 was below average (negative anomalies) in a large region extending from Greenland and Europe to Central Asia, northern Japan and the Kamchatka Peninsula in the Russian Federation.
These variations occur within the long-term trend towards the healing of the ozone layer, reflecting the success of the Montreal Protocol on Substances that Deplete the Ozone Layer , which phased out chemicals such as chlorofluorocarbons once found in refrigeration, fire-fighting foam and other common uses.
"This is an environmental success story. Since 2000, the ozone layer has been recovering, and we can expect full recovery within several decades," said WMO Secretary-General Celeste Saulo.
The WMO Global Atmosphere Watch (GAW) network provides the critical, high-quality ground-based total column ozone observations required to accurately monitor ozone and ensure that long-term changes can be understood.
