City Nature Challenge Events
Get outside and photograph nature! Go out on your own or with others. You can even join our partners at the events listed below. Be sure to check back in as we will continue to add new events.
Can’t get outside? No problem. Take part from the comfort of a desktop computer and help identify the plants and animals people observe with their cameras. Find more information on how to identify observations.
We are encouraging everyone to follow recommended protocols related to staying healthy, keeping safe, and staying respectful of wildlife and wild spaces.
2026 City Nature Challenge
Stay tuned for City Nature Challenge 2026 Events!
Leading up to the challenge
Thursday, April 9
Thursday, April 16
Thursday, April 23
Friday, April 24
Saturday, April 25
- Hidden Habitats Hike in Carlsbad
- 8-9 AM, Saturday, April 25
- Hosted by California State Parks
- Registration Required.
- Kumeyaay Lake Campground Nature Walk for City Nature Challenge
- Cabrillo National Monument BioBlitz
- 8:30 AM-10:30 PM
- Hosted by Cabrillo National Monument
- This event will include guided walks throughout the day.
- Register by emailing CABR_Education@nps.gov
- Spanish-speakers available.
- Earth Day BioBlitz at Torrey Pines
- 9 AM, 10 AM, & 11 AM, Saturday, April 25
- Hosted by Torrey Pines State Natural Reserve & the Torrey Pines Docent Society
- Stop by the booth for instructions or join a guided walk at the above times.
- BioBlitz and Spring Flower Hike on San Diego NWR
- 9-11 AM, Saturday, April 25
- Hosted by Earth Discovery Institute
- Tidepooling Adventures at Scripps
- 11:15 AM-12:45 PM, Saturday, April 25
- Hosted by Birch Aquarium at Scripps
- Registration Required. Participants must be at least 6 years old.
- Bilingual BioBlitz with Bugologist
- 9-11:30 AM, Saturday, April 25
- Hosted by Bugologist
- Bilingual in English and Spanish
- Creek to Bay Cleanup
- 9 AM-12 PM, Saturday, April 25
- Hosted by I Love a Clean San Diego
- Make some observations while you clean at one of the 100 sites around the county.
- iNaturalist Walk at Torrey Pines
- 10 AM-12 PM, Saturday, April 25
- Hosted by the Geography Club at UCSD
- City Nature Challenge BioBlitz at Grande Caribe Shoreline Park
- 1-3 PM, Saturday, April 25
- Hosted by Coronado Public Library
- Afternoon BioBlitz at Elliott Chaparral Reserve
- 2-4 PM, Saturday, April 25
- Hosted by UC San Diego Natural Reserve System & The Nat
- Bilingual Nighttime BioBlitz with Bugologist
- 6:30-8:30 PM, Saturday, April 25
- Hosted by Bugologist at Rice Canyon Demonstration Gardens
- Bilingual in English & Spanish
- Self-guided observations:
- Head outside and use the iNaturalist app to make observations of all the wild plants and animals you encounter in San Diego County. Check out the San Diego County City Nature Challenge project to take the challenge! New to the app? Check out our tutorial here.
Sunday, April 26
Monday, April 27
After the Challenge
The observation period this year is from Tuesday, April 28 through Sunday, May 10.
Be sure to check this page for updates. We will add events as they are scheduled.
Want to host an event? Contact our community science team.
Be sure to check this page for updates. We will add events as they are scheduled.
Want to host an event? Contact our community science team.
Border BioBlitz 2026
This year, City Nature Challenge overlaps with the 2026 Border BioBlitz/BioBlitz de la Frontera. The Border BioBlitz is a community science effort to record as many species as possible along the U.S.-Mexico border and is made possible thanks to partnerships with Botanical Community Development Initiatives, Next Generation Sonoran Desert Researchers, and community members like you!
To join the discovery, all you need is a smartphone with the iNaturalist app (free for Android and iOS) and to join the project. You can make observations on your own, or join a community Border BioBlitz event! By joining the project during the City Nature Challenge, you can ensure that your observations count for both!
Want to stay involved past this event? Learn more about The Nat’s ongoing community science projects.
