International Cli-Fi Day, also known as Climate Fiction Day, is observed worldwide every April 20 to celebrate the genre of climate fiction, which addresses climate change and its effects on society and the environment. The term "cli-fi" was coined by climate activist Dan Bloom in the late 2000s, with roots in literature dating back to the late 19th century, including works like Jules Verne’s *The Purchase of the North Pole*. The genre gained further prominence with Frank Herbert's 1965 novel *Dune*, which explores ecological themes. Celebrations of International Cli-Fi Day can include reading cli-fi literature, watching related films, participating in book clubs, or organizing community events focused on climate change awareness. Participants are encouraged to share their activities on social media using hashtags like #InternationalCliFiDay and #ClimateFictionDay.