The San Diego Regional Report includes climate science, impacts, and adaptation information for San Diego County.
San Diego, California’s southernmost coastal county, has a Mediterranean climate with warm, sunny summers and mild, sometimes rainy winters, and some of the most variable annual precipitation in the United States. Dramatic contrasts unfold over short distances, from the cool coast across inland mountains to the arid Anza-Borrego Desert, making San Diego County one of the most biodiverse in the nation. The Tribal Nations of the region – the Cahuilla, Kumeyaay (Diegueño), Kuupangaxwichem (Cupeño), and Payómkawichum (Luiseño) – have supported and maintained the region’s biodiversity through generations of stewardship.
About half of San Diego County’s land is under some form of environmental protection. In addition to the 17 federally recognized and one non-federally recognized tribal governments, the region includes 17 incorporated cities and the unincorporated county, coordinated in regional planning by the San Diego Association of Governments (SANDAG). Nearly 3.3 million residents live in the county, with most concentrated near the coast.
Prominent sectors of San Diego’s economy include services, research and development, manufacturing, agriculture, and tourism. While agriculture is a small share of regional GDP, San Diego has the most small farms of any county in the United States. The region also maintains strong social and economic ties with Mexico as part of the Cali–Baja region, which includes the busiest land-border crossing in the US.
Climate models project that climate change impacts will vary across San Diego’s diverse climate zones. Coastal communities face increasing coastal flooding from sea level rise, while inland communities are disproportionately exposed to rising heat and wildfire risk, particularly during Santa Ana wind events. Socially vulnerable populations, concentrated near San Diego Bay as well as inland in El Cajon and Escondido, often experience the most severe impacts. Through its strong research institutions and culture of innovation, San Diego models resilience planning guided by science and information.
San Diego Regional Report
Coordinating Lead Authors
Julie Kalansky and Tom Corringham, Scripps Institution of Oceanography, UC San Diego