# Antarctic ozone hole status and recovery

> Live situation record from CLSTR: https://clstr.news/situations/antarctic-ozone-hole-status-and-recovery
> Updated: 2026-09-21T10:10:00.000Z. Sources: 73. Developments: 2.

The Antarctic ozone hole has shown significant seasonal and long-term fluctuations. In September 2026, the hole expanded rapidly to an estimated 25 million square kilometers, which was approximately five million square kilometers larger than the historical average for that period.

However, this seasonal expansion exists within a broader context of gradual recovery. Reports from 2025 indicated the ozone hole reached one of its smallest sizes in two decades, with depth and extent significantly lower than historical averages recorded between 1990 and 2010. According to the World Meteorological Organization (WMO), for the second consecutive year, the hole's size remained significantly below the historical average recorded between 1990 and 2010.

This recovery is attributed to the success of the Montreal Protocol, an international treaty signed by 197 countries and the European Union to phase out ozone-depleting substances like chlorofluorocarbons (CFCs). The production and consumption of these chemicals have decreased by over 99 percent. While the ozone layer shows signs of steady regeneration, experts suggest full recovery may still take several decades, with some estimates suggesting it could reach full recovery by approximately 2050. Despite these trends, some data indicates that ultraviolet radiation has increased by up to 20 percent in parts of Europe since 1995.

## Claims

- The Antarctic ozone hole in 2025 was one of the smallest in recent decades. (disputed by 3 sources)
- The ozone hole reached approximately 25 million square kilometers by late September this year. (disputed)
- For the second consecutive year, the ozone hole size remained significantly below the 1990–2010 average. (corroborated by 2 sources)
- The ozone layer is expected to fully recover by approximately 2050. (single source)
- The production and consumption of ozone-depleting substances have decreased by more than 99 percent. (single source)
- Ultraviolet radiation has increased by up to 20 percent in some parts of Europe since 1995. (single source)

## Timeline

### 2026-09-21: Antarctic ozone hole reaches one of its smallest sizes in decades

The Antarctic ozone hole was among its smallest in decades in 2025, signaling progress in ozone layer recovery driven by the Montreal Protocol's phase-out of harmful chemicals.

4 sources. https://clstr.news/cluster/antarctic-ozone-hole-shows-signs-of-recovery

### 2026-09-15: Antarctic ozone hole reaches 25 million square kilometers

The Antarctic ozone hole reached approximately 25 million square kilometers in mid-September 2026, exceeding seasonal averages, though scientists report a long-term recovery trend due to the Montreal Protocol.

69 sources. https://clstr.news/cluster/germany-weather-forecast-predicts-late-summer-heatwave

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Cite as: Antarctic ozone hole status and recovery. CLSTR, https://clstr.news/situations/antarctic-ozone-hole-status-and-recovery