San Diego County, CA

The USDA Economic Research Service Food Access Research Atlas flags 288 of San Diego County's 822 census tracts as low-access, covering 921,116 residents of a 3.3M total population. That translates to a county-wide low food access share of 28.0%, which measures how many people live more than one mile from the nearest supermarket in urban settings or more than ten miles in rural settings. Because California classifies tracts using the same distance thresholds the USDA applies nationwide, San Diego County's figure is directly comparable to peer counties and to the state benchmark.

The food desert signal strengthens when distance is stacked with income. In San Diego County, 207,232 residents are flagged as low-income and more than one mile from a supermarket (the urban threshold), while 69,077 meet the low-income, ten-mile rural threshold. Those overlapping conditions are the precise combination the USDA uses to designate a food desert tract. Layered context includes a median household income of $96,974, a poverty rate of 10.6%, and SNAP participation covering 94,795 households — roughly 8.2% of the county — drawn from the Census Bureau American Community Survey five-year estimates.

Transportation is the hidden variable behind most food access gaps. About 5.4% of San Diego County households report no vehicle available, meaning any measured distance to a supermarket translates into a real trip on foot, by transit, or by asking for a ride. Group quarters residents — 3.0% of the population — are counted separately because their food access patterns follow an institution rather than a household. The county's low-access share sits near or below the typical U.S. county, but tract-level variation can still produce pockets of food desert conditions inside otherwise well-served areas.