Overview
- From September 7 to October 13, the ozone hole averaged about 7.23 million square miles, peaking at 8.83 million on September 9.
- The 2025 hole began breaking up nearly three weeks earlier than the average over the past decade.
- A weaker-than-normal polar vortex in August likely limited depletion by keeping stratospheric temperatures above average.
- South Pole balloon soundings found a seasonal low of 147 Dobson Units on October 6, compared with the 2006 record low of 92.
- NOAA and NASA report ozone-depleting substances have fallen by about one-third since around 2000, and estimate this year’s hole would be over one million square miles larger with late‑1990s chlorine levels.