Persistent cold temperatures and strong circumpolar winds supported the formation of a large and deep Antarctic ozone hole in 2020, and it is likely to persist into November, NOAA and NASA scientists reported. On September 20, 2020, the annual ozone hole reached its peak area at 24.8 million square kilometers (9.6 million square miles), roughly three times the size of the continental United States. Last year’s ozone hole was the smallest since the early 1980s, growing to 16.4 million square kilometers (6.3 million square miles) in early September. During recent years with normal weather conditions, the ozone hole has typically grown to a maximum of 20 million square kilometers (8 million square miles). In addition to the area of the ozone hole, scientists also track the average amount of ozone depletion—how little is left inside the hole.