January
Australia Day – 26th
February
World Wetlands Day – 2nd
International Day of Women & Girls in Science – 11th
International Polar Bear Day – 27th
March
First day of Autumn – 1st
Clean Up Australia Day – 3rd
World Wildlife Day – 3rd
SeaWeek – 4 to 12 March 
Parks Week – 4 to 12 March
International Women’s Day – 8th
Global Recycling Day – 18th
Sustainable Seafood Week – Commences 18th
World Sparrow Day – 20th
International Day of Forests – 21st
Harmony Week – Commences 20th
World Water Day – 22nd
National Ride2School Day – 22nd
World Meteorological Day 23 March 
Earth Hour Schools Day 24 March 
Earth Hour – 25th
April
National Trust Heritage Festival – 1st April to 14th May ​(state dates vary)
International Day for Monuments and Sites – 18th
World Fish Migration Day – 21st
Earth Day – 22nd
Anzac Day – 25th
May
International Day for Biological Diversity – 22nd
Greenery Day – 4th
Endangered Species Day – Third Friday May
International Composting Awareness Week – 6th to 12th
World Migratory Bird Day – 13th
Walk Safely to School Day – 19th
National Volunteer Week – 21st to 27th
International Day for Biological Diversity – 22nd
World Turtle Day – 23rd
National Sorry Day – 26th
National Reconciliation Week – 27th to 3rd June
June
First day of Winter – 1st
World Environment Day – 5th
World Oceans Day – 8th
Global Wind Day – 15th
World Sea Turtle Day – 16th
World Day to Combat Desertification and Drought – 17th
World Giraffe Day – 21st
UN International Yoga Day – 21st

July
Plastic Free July – All month
NAIDOC Week – 2nd to 9th
World Population Day – 11th
Schools Tree Day – 28th
National Tree Day – 30th
International Tiger Day – 29th
August
Jeans for Genes Day – 4th
International Day for World Indigenous Peoples – 9th
World Lion Day – 10th
Red Nose Day – 11th
World Elephant Day – 12th
National Science Week – 12th to 20th
International Youth Day – 12th
World Humanitarian Day – 19th
National Honey Bee Day – 20th
September
First day of Spring – 1st
National Biodiversity Month – All month
National Wattle Day – 1st
Sea Week – TBC
National Landcare Week – 7th to 13th
National Threatened Species Day – 7th
National Bilby Day – 9th
Sustainable House Day – 16th
World Water Monitoring Day – 18th
World Car-Free Day – 22nd
World Environmental Health Day – 26th
World Maritime Day – 29th
October
World Habitat Day – 3rd
World Animal Day – 4th
World Space Week – 4th to 10th
National Walk to Work Day – 5th
International Day for Disaster Reduction – 13th
World Food Day – 16th
International Day for the Eradication of Poverty – 17th
Aussie Bird Count – 16th to 22nd
Ride2Work Day – 18th
United Nations Day – 24th
International Day of Climate Action – 24th
World Day for Audiovisual Heritage – 27th
November
Outdoor Classroom Day – 2nd
FrogID Week – 3rd to 12th
National Recycling Week – 6th to 12th
Garage Sale Trail – 11th to 19th
Australian Pollinator Week – 11th to 19th
World Fisheries Day – 21st
December
First day of Summer – 1st
International Day of People with Disability – 3rd
World Soil Day – 5th
International Human Rights Day – 10th
International Mountain Day – 11th