An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Current State of the Ozone Layer

Atmospheric levels of ozone-depleting substances (ODSHelpODSA compound that contributes to stratospheric ozone depletion. ODS include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl bromide, carbon tetrachloride, hydrobromofluorocarbons, chlorobromomethane, and methyl chloroform. ODS are generally very stable in the troposphere and only degrade under intense ultraviolet light in the stratosphere. When they break down, they release chlorine or bromine atoms, which then deplete ozone. A detailed list ( of class I and class II substances with their ODPs, GWPs, and CAS numbers are available.) rapidly increased before the implementation of the Montreal Protocol on Substances that Deplete the Ozone Layer and its subsequent revisions and amendments. However, the atmospheric levels of nearly all these substances have declined substantially in the past two decades.

Continued declines in ODS emissions are expected to result in a near complete recovery of the ozone layer near the middle of the 21st century. The long time scale for this recovery is due to the slow rate at which ODS are removed from the atmosphere by natural processes.

Many organizations monitor the status of the ozone layer:

This is the most recent World Meteorological Organization (WMO) and United Nations Environmental Programme (UNEP) assessment. It contains the most up-to-date understanding of ozone depletion and reflects the thinking of over 312 international scientific experts who contributed to its preparation and review. A related document provides Questions and Answers about the Ozone Layer: 2014 Update.Exit

From UNEP, this report highlights the latest data and research into environmental effects of ozone depletion and its interactions with climate change.

View a page from the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center's website, which shows weekly updates of the hole.

ESRL's Global Monitoring Division conducts research on the depletion of the global stratospheric ozone layer and Antarctic ozone.

Provides current satellite ozone maps, the ultraviolet UVUVUltraviolet radiation is a portion of the electromagnetic spectrum with wavelengths shorter than visible light. The sun produces UV, which is commonly split into three bands: UVA, UVB, and UVC. UVA is not absorbed by ozone. UVB is mostly absorbed by ozone, although some reaches the Earth. UVC is completely absorbed by ozone and normal oxygen. NASA provides more information on their web site ( index bulletin, and other data and images.

Provides live data from satellites that monitor stratospheric ozone and UV radiation.

Includes information about WMO's atmospheric monitoring and research.

  • NASA provides daily images, data, and information from satellite instruments that monitor the ozone layer and the ozone hole, a thinning break in the stratospheric ozone layer. Designation of amount of such depletion as an "ozone hole" is made when the detected amount of depletion exceeds fifty percent. Seasonal ozone holes have been observed over both the Antarctic and Arctic regions, part of Canada, and the extreme northeastern United States.