January
- 5 National Bird Day
- 10 Cut Your Energy Costs Day
- 20 Penguin Awareness Day
February
- 2 World Wetlands Day
- 11 International Day of Women and Girls in Science
- 22 National Wildlife Day
- 27 International Polar Bear Day
- 28 National Skip the Straw Day
March
- 3 World Wildlife Day
- 8 International Women's Day
- 12 Solar Appreciation Day
- 14 International Day of Action for Rivers
- 18 Global Recycling Day
- 20 World Sparrow Day
- 21 International Forest Day
- 22 World Water Day
- 23 World Meteorological Day
- 27 Earth Hour
April
- Earth Month
- 1 Fossil Fools Day
- 3 World Aquatic Animal Day
- 11-17 Dark Sky Week
- 17-25 National Parks Week
- 18 World Heritage Day (International Day for Monuments and Sites)
- 19-23 National Environmental Education Week
- 22 Earth Day
- 22 International Mother Earth Day
- 24 Save the Frogs Day
- 25- May 3 World Parks Week
- 25- May 2 Stewardship Week
- 30 Arbor Day
May
- American Wetlands Month
- National Bike Month
- Bike Safety Month
- 2-8 International Compost Awareness Week
- 3-9 Screen Free Week
- 8 World Migratory Birds Day (Spring)
- 20 World Bee Day
- 21 Bike There Day/Bike to Work Day
- 21 Endangered Species Day
- 21 World Fish Migration Day
- 22 International Day for Biological Diversity
- 23 World Turtle Day
- 31- June 4 EU Green Week
June
- Great Outdoors Month
- 3 World Bicycle Day
- 5 World Environment Day
- 5 National Trails Day
- 7 World Food Safety Day
- 8 World Oceans Day
- 14-20 International Men's Health Week
- 15 Global Wind Day
- 17 World Day to Combat Desertification and Drought
- 18 Sustainable Gastronomy Day
- 21-27 Pollinator Week
- 22 World Rainforest Day
- 29 International Day of the Tropics
July
- Park and Recreation Month
- 1-7 Clean Beaches Week
- 3 International Plastic Bag Free Day
- 11 World Population Day
- 26 International Day for the Conservation of the Mangrove Ecosystem
- 29 International Tiger Day
August
- 9 International Day of the World's Indigenous People
- 12 International Youth Day
- 12 World Elephant Day
- 19 Orangutan Day
- 19 World Humanitarian Day
- 26 National Women's Equality Day
- 29 International Day Against Nuclear Tests
September
- 4 National Wildlife Day
- 5 International Day of Charity
- 7 International Day of Clean Air for Blue Skies
- 16 International Day for the Preservation of the Ozone Layer
- 18 International Coastal Cleanup Day
- 20 Sustainable House Day
- 21 Zero Emissions Day
- 21 International Day of Peace
- 22 World Car Free Day
- 26 World Rivers Day
- 29 International Day of Awareness of Food Loss and Waste
October
- Photographer Appreciation Month
- 1-7 Junk Mail Awareness Week
- 1 World Vegetarian Day
- 2 World Farm Animals Day
- 4 World Animal Day
- 4 World Habitat Day
- 4 Children's Health Day
- 6 Energy Efficiency Day
- 8 Hydrogen and Fuel Cell Day
- 9 World Migratory Bird Day (Fall)
- 11 Indigenous Peoples' Day
- 13 International Day for Natural Disaster Reduction
- 16 World Food Day
- 17 International Day for the Eradication of Poverty
- 23 International Snow Leopard Day
- 24 United Nations Day
- 24 International Day of Climate Action
November
- Men's Health Awareness Month (Movember)
- 1-12 United Nations Climate Change Conference
- 1 World Vegan Day
- 5 World Tsunami Awareness Day
- 13 World Kindness Day
- 15 America Recycles Day
- 20-28 European Week For Waste Reduction
- 21 World Fisheries Day
- 29 International Jaguar Day
December
- 4 Wildlife Conservation Day
- 5 International Volunteer Day
- 5 World Soil Day
- 10 Human Rights Day
- 11 International Mountain Day