Planning resilient urban forests will ensure that benefits of urban trees are maintained as the climate in California continues to change. Selecting species that are well-suited for future climatic conditions will be a key component of this strategy. Tree species that are adapted to warm and dry climates will likely perform well in California’s future climate. To understand the climatic requirements of urban tree species, we utilized data from the California Urban Forest Inventory and GBIF occurrence data from each species’ native range. We used various ordination approaches to (1) characterize each species’ climatic niche, (2) compare climatic niche of urban and native tree populations, and (3) develop region- and species-specific climate suitability scores for current and future climatic conditions in California. The results from this study can help guide species selection and planning for resilient urban forests, and suitability will be available to the public via the most widely-used tree website in the United States: SelecTree. The methods used here are also widely applicable to seed-sourcing efforts for ecological restoration or conservation.