This year's ozone hole over the Antarctic was the largest in a decade, according to a new report by NOAA and NASA.

The 2026 ozone hole became the seventh largest in 48 years of monitoring, fueled by an unusually powerful polar vortex which prolonged ozone depletion in the Antarctic and allowed the hole to grow larger, researchers explained.

This is a stark contrast to 2025, when the ozone hole ranked as the fifth smallest since 1992. "The polar vortex was unusually large this year in part because planetary-scale weather systems that typically well up from the lower atmosphere and break up the vortex were especially weak in August and September," said Amy Butler, a research scientist at NOAA's Chemical Sciences Laboratory.