San Marcos is a city in northern San Diego County, California. As of the 2010 census the city’s population was 83,781. It is the site of California State University, San Marcos. San Marcos is bordered by Escondido to the east, Encinitas to the southwest, Carlsbad to the west, and Vista to the northwest. Lake San Marcos is an enclave, or county island, in the southwestern part of the city, within San Marcos’s sphere of influence but technically an unincorporated community.
According to the United States Census Bureau, the city has a total area of 24.4 square miles (63 km2). 24.4 square miles (63 km2) of it is land and 0.02 square miles (0.052 km2) of it (0.08%) is water. Due to the moderating influence of the nearby Pacific, temperatures rarely fall below freezing in winter and above 100 degrees F. in summer. Most of the rain falls in San Marcos between November and March, averaging about 13 inches per year, with up to 20 inches falling in the San Marcos Hills.
US Census Data reports that the median home price for owner-occupied housing units in 2017 was $455,700, placing San Marcos into one of the more affordable locations in San Diego County