The City Nature Challenge or CNC is a global challenge using citizen science to document wildlife in cities.

Our geographic area will include all of Metro Phoenix and much of Maricopa County. Our iNaturalist project will provide you with exact boundary information.   

Citizen science invites anyone, regardless of scientific training, to help collect and contribute data for scientific research projects of all sizes.

The City Nature Challenge puts this idea into a fun, friendly competition! Participants document wildlife across the region, generating valuable data that scientists can use to study biodiversity.

The City Nature Challenge takes place annually on the final weekend of April. In 2026, observation dates are April 24–27.

After the observation period, you have until May 10 to upload your photos and identify your observations in iNaturalist. The goal is to identify organisms to the exact species when possible to support biodiversity research—but any level of identification is helpful!

iNaturalist is a free app used to document wildlife. Anyone can participate and anyone can use the data to learn more about wildlife in a given area.

The easiest way is to go to the “City Nature Challenge [year]: Greater Phoenix Area” project on iNaturalist, click the “Observers” tab, and look for your username there!

If you’ve joined your city’s project, you can also look at your individual observations and you’ll see your city’s project listed under the “Projects” sidebar. 

Yes, as long as you’re not making a lot of these observations, most cities will include observations of non-wild organisms during the CNC. However, it’s VERY IMPORTANT TO MARK THOSE OBSERVATIONS AS CAPTIVE/CULTIVATED. Please be a good community member and data steward by marking any observation that you know for sure is not wild as captive/cultivated - in iNaturalist, there’s a field for it in the app when you make an observation. This includes pets, animals in a zoo/aquarium, plants in your garden, potted plants, plants at a botanical garden, etc. Here’s a very short video on how to mark observations as captive/cultivated.