International Day for the Preservation of the Ozone Layer

The International Day for the Preservation of the Ozone Layer on September 16 marks the 1987 signing of the Montreal Protocol. It is a UN science-and-treaty date.

ozoneMontreal ProtocolSeptemberUnited Nationsenvironment

International Day for the Preservation of the Ozone Layer - The International Day for the Preservation of the Ozone Layer on September 16 marks the 1987 signing of the Montreal Protocol. It is a UN science-and-treaty date.

About International Day for the Preservation of the Ozone Layer

History & origins

September 16, 1987, is the date of the Montreal Protocol on substances that deplete the ozone layer. The UN marks the anniversary as the International Day for the Preservation of the Ozone Layer.

Why it matters

The day is a rare environmental-treaty success story, not a generic ‘earth day’ duplicate.

How to celebrate

Read what the Montreal Protocol actually banned, and skip ozone-hole denial. Everyday aerosol myths are often out of date.

Facts

The Montreal Protocol was signed on September 16, 1987
The UN observes the day on that anniversary
It is not a U.S. federal holiday

Upcoming dates

Wednesday, September 16, 2026
Thursday, September 16, 2027
Saturday, September 16, 2028
Sunday, September 16, 2029
Monday, September 16, 2030

Frequently asked questions

When is International Day for the Preservation of the Ozone Layer in 2026?

International Day for the Preservation of the Ozone Layer in 2026 falls on Wednesday, September 16, 2026.

What is the Montreal Protocol?

A 1987 treaty to phase out ozone-depleting substances.

Who created the day?

The United Nations, on the protocol’s anniversary.

Is it a U.S. holiday?

No.

Help others discover this day by sharing it.

Explore more

Full calendar More International days All categories Home

Related days

International Women's Day

Celebrate the achievements and contributions of women worldwide on International Women's Day! This global day recognizes the social, economic, cultural, and political achievements of women while calling for gender equality. Join the movement to create a more inclusive world where women and girls can reach their full potential.

World Environment Day

Protect our planet and promote environmental awareness on World Environment Day! This global celebration encourages individuals and communities to take action for environmental protection and sustainability. Learn about environmental challenges, discover eco-friendly practices, and join millions worldwide in making a positive impact on our Earth's future.

International Day of Clean Air

Breathe easier and take action for clean air on International Day of Clean Air! Air pollution affects billions of people worldwide and contributes to climate change. Learn about air quality, support clean air initiatives, and discover ways to reduce your personal contribution to air pollution.

International Day of Democracy

The International Day of Democracy on September 15 is a United Nations date for democratic institutions and participation. It is not a U.S. partisan holiday.

International Day of Peace

Promote peace and unity around the world on International Day of Peace! This United Nations observance encourages all nations and peoples to honor a cessation of hostilities and to commemorate peace through education and public awareness. Join the global movement for peace, understanding, and cooperation among all people.