| World Wetlands Day |
02-02: February 2 |
| International Polar Bear Day |
02-27: February 27 |
| World Wildlife Day |
03-03: March 3 |
| Solar Appreciation Day |
Second Friday of March |
| International Day of Action for Rivers |
03-14: March 14 |
| World Consumer Rights Day |
03-15: March 15 |
| World Sparrow Day |
03-20: March 20 |
| International Day of Forests |
03-21: March 21 |
| World Planting Day |
03-21: March 21 |
| World Wood Day |
03-21: March 21 |
| World Water Day |
03-22: March 22 |
| Earth Day |
04-22: April 22 |
| World Fish Migration Day |
April 21, 2018 |
| Day of Remembrance for all Victims of Chemical Warfare |
04-29: April 29 |
| Green Up Day |
05: first Saturday of May in Vermont |
| Greenery Day |
05-04: May 4 in Japan (previously April 29) |
| World Migratory Bird Day |
second Saturday in May |
| International Migratory Bird Day |
second Saturday in May (in the U.S. and Canada) and second Saturday in October (in Mexico, Central and South America, and the Caribbean) |
| International Recycling Day |
May 17th, 2017 |
| Endangered Species Day |
05-19: May 19 |
| International Day for Biological Diversity (World Biodiversity Day) |
05-22: May 22 |
| World Turtle Day |
05-23: May 23 |
| European day of parks (Europarc) |
05-24: May 24 |
| Bike-to-Work Day |
05: third Friday in May |
| World Environment Day |
06-05: June 5 |
| World Oceans Day |
06-08: June 8 |
| Coral Triangle Day |
06-09: June 9 |
| Global Wind Day |
06-15: June 15 |
| World Sea Turtle Day |
06-16: June 16 |
| World Day to Combat Desertification and Drought |
06-17: June 17 |
| World Giraffe Day |
06-21: June 21 |
| World Population Day |
07-11: July 11 |
| International Tiger Day |
07-29: July 29 |
| World Lion Day |
08-10: August 10 |
| World Elephant Day |
08-12: August 12 |
| World Orangutan Day |
08-19: August 19 |
| National Honey Bee Day |
08-22: August 22 |
| Amazon Day |
09-05: September 5 |
| International Day for the Preservation of the Ozone Layer |
09-16: September 16 |
| World Cleanup Day |
09-15: September 15, 2018 |
| World Water Monitoring Day |
09-18: September 18 |
| Zero Emissions Day |
09-21: September 21 |
| Car Free Day |
09-22: September 22 |
| World Rhino Day |
09-22: September 22 |
| Ecological Debt Day (Earth Overshoot Day) |
09-23: September 23 in 2008, but receding |
| World Environmental Health Day |
09-26: September 26 since 2011 (IFEH) |
| World Rivers Day |
09: last Sunday in September |
| World Habitat Day |
10: first Monday in October |
| World Animal Day |
10-04: October 4 |
| Energy Efficiency Day |
10-05: October 5 since 2016 |
| International Day for Natural Disaster Reduction |
10: second Wednesday in October , October 13. |
| Sustainability Day |
10: fourth Wednesday of October |
| International Snow Leopard Day |
October 23 |
| International Day of Climate Action |
10-24: October 24 |
| World Vegan Day |
11-01: November 1 |
| International Day for Preventing the Exploitation of the Environment in War and Armed Conflict |
11-06: November 6 |
| America Recycles Day |
11-15: November 15 |
| World Soil Day |
12-05: December 5 |
| International Mountain Day |
12-11: December 11 |
| Ozone Action Day |
at certain times during the summer months |
| eDay |
variable date |
