The Antarctic ozone hole reached its annual maximum in September 2026, ranking as the seventh largest recorded in 48 years of satellite monitoring according to NASA. However, despite its extensive size the ozone hole was not as deep as several previous large ozone depletion events.
NASA’s observations revealed that the ozone hole reached its maximum area on September 18, 2026. Scientists identified an unusually strong Antarctic polar vortex as a major factor behind the extensive ozone depletion, creating favourable atmospheric conditions for the phenomenon to develop over a large region.
The measurements showed that the ozone hole was particularly extensive during the peak depletion season from September 7 to October 13. Its average size during this period placed it among the largest recorded since satellite monitoring began in 1979.
What Is the Antarctic Ozone Hole?
The ozone layer is a protective region of Earth’s stratosphere that absorbs harmful ultraviolet radiation from the Sun. Excessive exposure to this radiation can damage DNA in plants, animals and humans, increasing the risk of sunburn and skin cancer.
The term “ozone hole” does not mean that the atmosphere is completely empty of ozone. Instead, scientists use it to describe areas where ozone concentrations fall below 220 Dobson Units a measurement used to monitor atmospheric ozone levels.
The phenomenon attracted worldwide attention in 1985, when British Antarctic Survey scientists reported dramatic seasonal ozone depletion over Antarctica using ground based measurements at Halley Research Station.
NASA satellite observations subsequently revealed the full geographical extent of the thinning ozone layer.
Historical measurements show that the Antarctic ozone hole became progressively larger and deeper during the 1980s and early 1990s.
In 1979, its maximum depth was recorded at 194 Dobson Units. The depletion intensified in subsequent years, reaching 173 DU in 1982, 154 DU in 1983 and 124 DU in 1985.
By 1991, ozone concentrations had fallen below 100 DU for the first time. Such extremely low concentrations became increasingly common in later years.
The deepest ozone hole on record occurred in 1994, when ozone concentrations dropped to just 73 Dobson Units on September 30. Meanwhile, the largest ozone hole by area was recorded in 2006.
Interestingly, the records for the greatest depth and largest area occurred in different years.
How Human Activities Contributed to Ozone Depletion
Scientists identified chlorofluorocarbons (CFCs) as a major cause of ozone destruction. These long lasting chemicals were widely used in refrigerators, aerosol sprays and other industrial applications beginning in the 1930s.
CFCs can remain in the lower atmosphere for decades without breaking down. However, when they reach the stratosphere, ultraviolet radiation causes them to release chlorine atoms.
These chlorine atoms trigger chemical reactions that repeatedly destroy ozone molecules, gradually weakening Earth’s natural protective layer.
Human produced bromine compounds also contribute to ozone depletion. Although less abundant than chlorine, they can be considerably more destructive to ozone.
Growing international concern over ozone depletion led to the adoption of the Montreal Protocol in 1987. The international agreement established measures to phase out the production and consumption of ozone depleting substances, including CFCs.
The agreement marked a major global effort to protect Earth’s atmosphere.
In 2018, scientists reported direct satellite evidence of ozone recovery, identifying a 20 per cent reduction in ozone depletion during Antarctic winter months between 2005 and 2016.
Weather conditions also play an important role in annual changes. In 2019, unusual atmospheric patterns over Antarctica significantly restricted ozone depletion, producing the smallest ozone hole since 1982.
When Will the Ozone Layer Fully Recover?
Despite encouraging progress, scientists warn that ozone recovery will take several more decades because ozone depleting chemicals remain in the atmosphere for long periods.
Models suggest that concentrations of chlorine and other ozone destroying substances will not return to pre 1980 levels until later in the 21st century.
According to scientific estimates, the Antarctic ozone layer could recover to its 1980 levels during the 2070s.
NASA’s latest observations highlight both the continuing challenges of atmospheric ozone depletion and the importance of international environmental agreements. Although the 2026 ozone hole ranked among the largest on record, the long term recovery trend demonstrates that coordinated global action can help protect Earth’s atmosphere.