India is celebrating World Environment Day 2025 with unique, free events nationwide—plastic-free markets in Trichy, mega tree plantations in Andhra Pradesh, innovation fairs in Assam, and clean-ups in Varanasi and Goa. Mumbai will host a sustainability conference at NSE Auditorium from 1:00 pm to 5:30 pm. Delhi is holding citywide plantation drives. All events are open for public participation.