Unite with cities worldwide to explore and document urban biodiversity during the 2026 City Nature Challenge.
The countdown to the 2026 City Nature Challenge (CNC) has officially begun, and cities around the world are gearing up for this extraordinary event! What started as a friendly competition between Los Angeles and San Francisco in 2016 has blossomed into a global movement, uniting communities in a shared mission to explore, document, and celebrate the natural world in urban environments.
Organized by the Community Science teams at the California Academy of Sciences and the Natural History Museum of Los Angeles County, the CNC is an annual four-day bioblitz held at the end of April. It’s a unique blend of collaboration and friendly competition, where cities work together to uncover the incredible biodiversity that thrives in their own backyards.
Mark Your Calendars: Key Dates for CNC 2026
The 2026 City Nature Challenge will take place in two exciting phases:
April 24 – April 27, 2026: Participants will head outdoors to capture photos of wild plants, animals, and other signs of life in their cities.
April 28 – May 10, 2026: The focus shifts to identifying and cataloging the observations made during the first phase.
The results of this global effort will be announced on Monday, May 13, 2026, showcasing the collective impact of participants worldwide.
How to Participate
Getting involved in the City Nature Challenge is simple and rewarding:
Find Wildlife: Look for any wild plant, animal, or evidence of life in your city. Whether it’s a bird perched on a tree, a butterfly in a garden, or a mushroom growing in a park, every observation counts.
Take a Picture: Snap a photo of your discovery and make sure to note its location.
Share Your Findings: Upload your observations to iNaturalist or your city’s designated platform to contribute to the global database.
Why It Matters
The City Nature Challenge is more than just a fun activity—it’s a powerful tool for science and conservation. By participating, you’re helping researchers better understand urban biodiversity and how humans coexist with nature. The data collected during the CNC has already contributed to numerous scientific studies, shedding light on species distribution, migration patterns, and the effects of urbanization on wildlife.
In 2025 alone, CNC participants made over 3.3 million observations, identified 73,765 species, and engaged more than 102,000 people worldwide. These impressive numbers highlight the growing impact of this initiative and the enthusiasm of citizen scientists everywhere.
Calling All Local Organizers
If you’re passionate about nature and want to bring the CNC to your community, now is the time to get involved! Local organizers play a crucial role in rallying participants, coordinating events, and ensuring the success of the challenge in their cities. Visit the CNC Organizer page to learn more and subscribe to the email list for updates on upcoming meetings and resources.
Join the Movement
The City Nature Challenge is a celebration of the incredible diversity of life that surrounds us, even in the most unexpected places. It’s a chance to connect with nature, contribute to meaningful scientific research, and foster a deeper appreciation for the ecosystems that sustain us.
So, grab your camera, lace up your walking shoes, and get ready to explore the wild side of your city. Together, we can make the 2026 City Nature Challenge the most impactful one yet!
#CityNatureChallenge #UrbanBiodiversity #CitizenScience
