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Where in Earth’s atmosphere is most of the ozone layer located?

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ozone depletion — Ozone depletion The Antarctic ozone hole reaches its maximum extent in October of each year. On October 7, 2021, when this image was captured, the Antarctic ozone hole spanned 24.8 million square km (9.6 million square miles).

Most of the Earth's ozone is located in the stratosphere, a layer of the atmosphere that extends from approximately 10–18 km (6–11 miles) to about 50 km (30 miles) above the surface. Approximately 90 percent of the atmosphere's ozone is found within this region.1

The ozone layer itself is generally situated between 15 and 35 km (9 and 22 miles) above the Earth's surface, though its peak concentration varies by latitude. For instance, peak concentrations occur at altitudes of 20 to 25 km (12 to 16 miles) in the midlatitudes, 26 to 28 km (16 to 17 miles) in the tropics, and 12 to 20 km (7 to 12 miles) near the poles.1

While the stratosphere contains the vast majority of this ozone, the remainder is found in the troposphere, where it can form as a component of photochemical smog due to human-generated pollutants.21