World Ozone Day
The ozone layer is healing — proof that global action works.
About
World Ozone Day, officially the International Day for the Preservation of the Ozone Layer, is observed on September 16 each year. The ozone layer absorbs most of the Sun's ultraviolet radiation, protecting life on Earth. The recovery of the ozone layer is widely regarded as one of the greatest environmental success stories of the 20th century.
History
September 16 marks the date in 1987 when the Montreal Protocol on Substances that Deplete the Ozone Layer was signed. The UN General Assembly designated the day in 1994. The Montreal Protocol has been ratified by all 197 UN member states — the only UN treaty to achieve universal ratification — and is credited with preventing millions of skin cancer cases.
Where It's Observed
How to Participate
- 01Learn what the ozone layer is and why it matters for life on Earth
- 02Dispose of old refrigerants and air conditioners through certified recyclers
- 03Check that aerosol products you use are CFC-free
- 04Share the Montreal Protocol success story as a model for climate action
Frequently asked questions
When is World Ozone Day?+
World Ozone Day is observed annually on September 16. The date is fixed each year — September 16 — and does not shift based on the lunar calendar or weekday.
What is World Ozone Day?+
World Ozone Day, officially the International Day for the Preservation of the Ozone Layer, is observed on September 16 each year. The ozone layer absorbs most of the Sun's ultraviolet radiation, protecting life on Earth. The recovery of the ozone layer is widely regarded as one of the greatest envir…
Is World Ozone Day a public holiday?+
World Ozone Day is an international observance or awareness day, not a public holiday in most countries. It does not typically result in days off work or school closures, though some countries and organisations hold official events.
How can I participate in World Ozone Day?+
Learn what the ozone layer is and why it matters for life on Earth Dispose of old refrigerants and air conditioners through certified recyclers Check that aerosol products you use are CFC-free These are some of the most accessible ways to engage with the day's purpose.
Which countries observe World Ozone Day?+
Global — United Nations Environment Programme initiative.
Mark the date
Download a free printable calendar for 2026 and never miss World Ozone Day.