NASA reported that the Antarctic ozone hole reached its 2026 maximum and was the seventh largest by area in 48 years of monitoring. It was shallower than other large holes in the record, according to a NASA Earth Observatory article.

The stratospheric ozone layer shields life by absorbing ultraviolet light. That light damages DNA in plants and animals, including people, and can cause sunburns and skin cancer, the article said. Scientists treat the hole as the region where ozone falls under 220 Dobson units, a level not seen before 1979.

The greatest area of the year was on Sept. 18, 2026. NASA judged the season by the hole’s average size from Sept. 7 to Oct. 13, the main period of ozone loss. A stronger-than-usual polar vortex over Antarctica set up conditions that favored loss across a wide area. Colder air higher in the atmosphere generally means a wider hole and less ozone at its center, the article said.

The word hole is a metaphor. No place is empty of ozone, NASA Earth Observatory said. The cutoff lets scientists describe both how wide the thin region is and how little ozone remains inside it.

Maps in the article show each year from 1979 through 2026, with no data for 1995, on the day when ozone was lowest. The 1979 low was 194 Dobson units. Later lows were 173 in 1982, 154 in 1983 and 124 in 1985. In 1991 the reading fell under 100 Dobson units for the first time. The deepest hole was in 1994, at 73 Dobson units on Sept. 30. The widest hole was in 2006. The record for depth and the record for area have never fallen in the same year.

From 1980 through the early 1990s the hole grew quickly in both width and depth, then roughly leveled off in the early 2000s. Differences from year to year come from changes in temperature and air movement in the stratosphere, according to the article.

The 2026 readings came from the Ozone Mapping and Profiler Suite on the NOAA-20 satellite. Earlier years used other instruments, including NASA’s Total Ozone Mapping Spectrometer, the Ozone Monitoring Instrument on the Aura satellite, and the same profiler suite on the Suomi NPP satellite.

In 1985, British Antarctic Survey scientists at Halley Research Station reported sharp springtime thinning over Antarctica from ground measurements. NASA satellites later showed that the thinning covered a continental scale.

Chlorofluorocarbons, chemicals used in refrigerators and aerosol sprays since the 1930s, last a long time near the ground. Higher up, ultraviolet light splits them and releases chlorine, which keeps destroying ozone, the article said. Scientists estimate that about 80 percent of the chlorine now in the stratosphere comes from human activity rather than natural sources. Bromine compounds made by people are far less common but much harder on ozone, and they also add to the Antarctic hole.

The 1987 Montreal Protocol is a treaty that phases out making and using ozone-depleting chemicals. Models suggest chlorine and related substances in the stratosphere will not be back to pre-1980 amounts until later this century, NASA Earth Observatory said. In 2018, scientists reported the first satellite evidence that ozone was recovering, with depletion during Antarctic winter months down 20 percent from 2005 to 2016. Unusual weather in 2019 produced the smallest hole since 1982. Scientists estimate the Antarctic ozone layer will be back to 1980 levels in the 2070s.

The article did not give the hole’s area in miles or kilometers, only its rank among 48 years of monitoring.