The ozone hole over Antarctica is significantly smaller in 2025 compared to previous years, ranking as the fifth-smallest since 1992, according to a report from NOAA and NASA scientists. In early September, the ozone hole reached its largest one-day extent for the year, measuring 8.83 million square miles. This size is approximately 30% smaller than the largest recorded hole, which occurred in 2006.

The term "ozone hole" refers to a large area in the Earth’s stratosphere with extremely low ozone concentrations, rather than an actual hole in the ozone layer. Scientists from NOAA and NASA highlight that recent findings demonstrate the effectiveness of efforts to limit ozone-depleting chemicals. These efforts are largely guided by the Montreal Protocol, which was implemented in 1992. Amendments to this protocol are contributing to the gradual recovery of the ozone layer, which is expected to fully recover later this century as countries transition to safer alternatives.

Paul Newman, a senior scientist at the University of Maryland and a leader of NASA’s ozone research team, stated, "This year’s hole would have been more than one million square miles larger if there was still as much chlorine in the stratosphere as there was 25 years ago."

For decades, chlorofluorocarbons (CFCs) and other ozone-depleting substances were commonly used in products like aerosol sprays, foams, air conditioners, and refrigerators, leading to significant reductions in ozone levels. Researchers also note that natural factors, including temperature and atmospheric circulation, likely played a role in this year's smaller ozone hole.

The ozone layer serves as a protective barrier, shielding humans, animals, and plants from harmful ultraviolet (UV) radiation. A decrease in ozone levels allows more UV rays to reach the Earth's surface, which can increase the risk of health issues such as skin cancer and cataracts, as well as environmental impacts like crop damage.