Antarctic ozone hole reaches 25 million km² as growth accelerates

The ozone hole reached 15 million km² by the end of August, slightly earlier than the long-term average and at a similar stage to the 2025 season. However, unlike last year, its area has remained above average as the Antarctic spring has progressed.

CAMS found that the ozone hole was around 5 million km² larger than average for this point in September. Forecasts indicated its area could increase further mid-month, although other measures of ozone depletion remained close to average.

The Antarctic ozone hole is defined as an area south of 60°S where ozone column concentrations fall below 220 Dobson Units (DU).

CAMS monitors the size of this region throughout the Antarctic spring, alongside other indicators including the minimum ozone column value, ozone mass deficit and stratospheric temperature.