California’s urban environments are made up of native and non-native species which all provide ecosystem services to urban residents. A species’ native status is often defined at the state scale, which doesn’t reflect the true native range of the species. In this research, we defined a list of native trees to California, created digital range maps for each species, created city-specific native species lists for every city in California, and analyzed trends in native tree species in California’s urban areas. We found that urban areas have relatively few tree species that are native to a city’s boundaries. Within California’s urban forests, we found that non-natives outnumber native plantings, despite that of the species native to each city, most cities plant nearly the full native species palette. California’s cities face a hotter and drier future, threatening existing urban forests and the benefits they bring to residents. Future species for planting should be diverse and selected based on their ability to survive the urban environment, using information on the species' physiology and conditions that the species is adapted to beyond a species' native status within a broad geopolitical boundary.