San Diego is a city located in Duval County Texas. It is also the county seat of Duval County. With a 2020 population of 4,205, it is the 408th largest city in Texas and the 5261st largest city in the United States . San Diego is currently declining at a rate of -0.19% annually and its population has decreased by -6.31% since the most recent census, which recorded a population of 4,488 in 2010. San Diego reached it's highest population of 5,225 in 1980. Spanning over 2 miles, San Diego has a population density of 2,212 people per square mile.
The average household income in San Diego is $42,680 with a poverty rate of 32.14%. The median rental costs in recent years comes to $669 per month, and the median house value is $36,600. The median age in San Diego is 33.7 years, 29.9 years for males, and 35 years for females.